Quantum and Nuclear Physics

ABSOLUTELY BLACK BODY
Is a model of a body that completely absorbs any electromagnetic radiation incident on its surface. The closest approximation to a completely black body is a device consisting of a closed cavity with an opening whose dimensions are small compared to the dimensions of the cavity itself.

ALPHA PARTICLE (α-particle)
- the nucleus of a helium atom. It contains two protons and two neutrons. The emission of α particles is accompanied by one of the radioactive transformations (alpha decay of nuclei) of some chemical elements.

ANNIHILATION
- This is one of the types of interconversion of elementary particles, in which a particle and its corresponding antiparticle are transformed into electromagnetic radiation.

ANTI-PARTICLES
- these are elementary particles that differ from the corresponding particles in the sign of electric, baryonic and lepton charges, as well as some other characteristics. The masses of particles and antiparticles are exactly the same. An antiparticle is most often denoted by the same symbol as the particle, but with a tilde at the top, for example: “n ~” is an antineutron, but an antielectron (positron) is indicated by “e +.” There are several particles that exactly match their antiparticles (for example , photon).

BARION CHARGE (baryon number) ((IMG :)
- the characteristic of elementary particles equal to +1 for baryons, –1 for antibaryons and 0 for all other particles. For example, for a proton b \u003d 1, for an antineutron b \u003d –1, for an electron b \u003d 0. There are no processes in nature in which a proton decays into other particles (for example, a positron and a gamma quantum are formed from a proton) and in which the law of conservation of energy, the law of conservation of momentum, and the law of conservation of charge would be fulfilled, can be interpreted as the law of conservation of baryon charge.

Beta Particle
- the electron emitted during beta decay. Beta particle flux is a type of radiation with a penetrating power greater than that of alpha particles, but less than gamma radiation.

HYDROGEN-LIKE ATOMS
- ions consisting, like a hydrogen atom, of a nucleus and one electron. These include ions of elements with an atomic number Z greater than or equal to 2, which have lost all electrons except one: He +, Li2 +, etc.

EXCITED STATE OF A QUANTUM SYSTEM
(atom, molecule, atomic nucleus, etc.) is an unstable state with energy exceeding the energy of the ground (zero) state.

FORCED RADIATION (induced radiation)
- this is electromagnetic radiation emitted by excited atoms or molecules under the influence of external radiation of the same frequency. The emitted stimulated emission coincides with the stimulating one, not only in frequency, but also in the direction of propagation, polarization and phase, not differing from it.

GAMMA RADIATION (gamma rays)
- short-wave electromagnetic radiation with a wavelength of less than 2 × 10–10 m. Due to the short wavelength, the wave properties of gamma radiation are weak, and they come to the fore corpuscular properties, in connection with which it is represented as a stream of gamma rays (photons). Being one of the three main types of radioactive radiation, gamma radiation accompanies the decay of radioactive nuclei. Of all types of radioactive radiation, gamma radiation has the largest penetrating power. Gamma radiation occurs not only during radioactive decays of nuclei, but also during the annihilation of particles and antiparticles, in nuclear reactions, during the deceleration of fast charged particles in matter (bremsstrahlung), during the decay of mesons, and is part of cosmic radiation.

HYPERONS
- These are elementary particles belonging to the class of baryons along with nucleons (proton, neutron). Hyperons are more massive than nucleons and have a non-zero characteristic of elementary particles called strangeness.

MAIN QUANTUM NUMBER (n)
Is an integer that determines the possible values \u200b\u200bof the energy of stationary states of hydrogen atoms and hydrogen-like atoms.

DEUTERIUM
- heavy stable isotope of hydrogen with a mass number of 2. The content of natural hydrogen is 0.156% (by weight).

Deuteron
Is the nucleus of an atom of deuterium. Consists of one proton and one neutron.

MASS DEFECT
- this is the difference between the sum of the masses of particles (bodies) forming a connected system, and the mass of this entire system. In classical Newtonian mechanics, mass is considered additive, the theory of relativity revealed the approximate nature of such a representation. Accurate measurements of the masses of the nuclei showed that the sum of the masses of the protons and neutrons forming the nucleus is greater than the mass of this nucleus.

DOSAGE OF RADIATION
Is a physical quantity that is a measure of the radiation exposure of living organisms to radioactive radiation or high-energy particles. A distinction is made between the absorbed dose of radiation, the equivalent dose and the exposure dose. Absorbed dose - the ratio of energy absorbed by the body to its mass. Measured in gray. Equivalent dose is the product of the absorbed dose and the radiation quality factor. It is measured in sievert and introduced due to the fact that the same energy of absorbed particles (for example, β-radiation and α-radiation) produces damage to a living organism of varying severity. To characterize the measure expected on the basis of biomedical studies of the radiation hazard of a particle, a radiation quality factor is introduced, which has a value of 1 to 20. The exposure dose is a quantitative characteristic of x-ray and γ-radiation, based on the ability to ionize air molecules. It is equal to the ratio of the total charge of ions of the same sign created in the air by electrons and positrons formed by this radiation to the mass of this air. In SI it is measured in pendants per kilogram. The non-systematic unit of the exposure dose is x-ray: 1 X-ray \u003d 0.258 microcoulomb per kilogram.

STEPHAN – BOLTZMAN LAW
- the energy emitted in one second by a unit surface area of \u200b\u200ba black body is directly proportional to the fourth degree of its absolute temperature.

LAW OF RADIOACTIVE DECAY
- the number of non-decayed radioactive nuclei in any sample is halved after each time interval, called the half-life. The law of radioactive decay is a statistical law and is valid for a sufficiently large number of radioactive nuclei. The half-life does not depend on external conditions and on the start time of the reference.

WINE DISPLACEMENT LAW
- with increasing temperature, the maximum energy in the emission spectrum of an absolutely black body shifts toward shorter waves, and moreover, so that the product of the wavelength that accounts for the maximum radiation energy and the absolute temperature of the body is constant.

LAWS OF EXTERNAL PHOTO EFFECT
1st law: the number of electrons knocked out by light of a given wavelength from a metal surface in 1 s is directly proportional to the light intensity;

2nd law: the maximum kinetic energy of electrons ejected by light increases linearly with the frequency of light and does not depend on its intensity;

3rd law: for each substance there is a red border of the photoelectric effect, i.e. such a minimum frequency of light (or maximum wavelength) at which a photoelectric effect is still possible, and if the frequency of light is less than this critical value, then the photoelectric effect does not occur.

ISOTOPES
- These are varieties of this chemical element that differ in the mass number of their nuclei. Isotopes of one element contain the same number of protons, but different numbers of neutrons. Having the same structure of electron shells, isotopes have almost the same chemical properties. However, the physical properties of isotopes can vary very sharply.

IONIZING RADIATION
- this is radiation, the interaction of which with the medium leads to the ionization of its atoms and molecules. This is x-ray radiation and γ-radiation, fluxes of β-particles, electrons, positrons, protons, neutrons, etc. Visible and ultraviolet radiation are not classified as ionizing radiation.

QUANTUM OF LIGHT (photon)
- a portion of the energy of electromagnetic radiation, an elementary particle, which is a portion of electromagnetic radiation, a carrier of electromagnetic interaction. A term used to describe light as a stream of neutral particles exhibiting wave properties in a number of experiments.

QUARKS
- These are point, structureless formations related to truly elementary particles, which were introduced to systematize the numerous (more than a hundred) elementary particles discovered in the 20th century (electron, proton, neutron, etc.). A characteristic feature of quarks, which is not found in other particles, is a fractional electric charge that is a multiple of 1/3 of the elementary charge. Attempts to detect quarks in a free state did not lead to success.

BODYWAVE DUALISM
- this is a universal property of nature, which consists in the fact that both corpuscular and wave features are manifested in the behavior of micro-objects. The term was introduced during the development of quantum physics, because according to the ideas of classical physics, the movement of particles (corpuscles) and the propagation of waves are fundamentally different physical processes. It turned out that in the physics of the microworld this idea is incorrect. It was found that the light to explain the laws of the photoelectric effect must be considered a stream of particles, and for electrons and protons, interference and diffraction can be observed.

NEUTRON BROADCASTING FACTOR
- this is a characteristic of the chain process of decay of radioactive nuclei, equal to the ratio of the number of neutrons in any generation of the chain reaction to the number of neutrons that generated them in the previous generation.

RED BORDER OF PHOTO EFFECT
Is the minimum frequency of light ν0 or the maximum wavelength λ0 at which the photoelectric effect is still possible.

CRITICAL MASS
Is the minimum mass of nuclear fuel at which a nuclear fission chain reaction is possible.

LASER (optical quantum generator)
- This is a light source operating on the principle of stimulated emission. The name "laser" (LASER) is formed by the first letters of the words of the English expression Light Amplification by Stimulated Emission of Radiation, which means "amplification of light using stimulated radiation." The high degree of coherence and sharp focus of laser radiation, as well as the ability to concentrate very high power in a pulse (with sufficient intensity, the laser beam melts and vaporizes any substance) has led to the widespread distribution of lasers in various fields of technology and medicine.

LINEAR SPECTRA
Are optical spectra consisting of individual spectral lines. Linear spectra are characteristic of the emission of heated substances in a gaseous atomic (but not molecular) state. The following regularity is characteristic of the line emission spectrum: the atoms of a given chemical element emit waves of a strictly defined set of frequencies; therefore, the line emission spectrum of each chemical element has its own, which does not coincide with the spectrum of any other chemical element. Not only the radiation spectrum, but also the absorption spectrum is ruled for individual atoms of a substance. The following regularity is true for the absorption spectrum: atoms of matter absorb light of precisely those frequencies that they emit in the heated state; therefore, the lines in the absorption spectrum of a given chemical element are located at the same places in the spectrum as the lines in the spectrum of its radiation.

LUMINESCENCE
- this is the body’s excess electromagnetic radiation over thermal (cold luminescence), caused either by electron bombardment of the substance (cathodoluminescence), or by passing an electric current through the substance (electroluminescence), or by the action of some kind of radiation (photoluminescence).

LUMINOPHORS
- these are solid and liquid substances capable of emitting light under the influence of electron flows (cathodoluminophores), ultraviolet radiation (photoluminophors), etc.

MASS NUMBER
Is the number of nucleons (protons and neutrons) in the atomic nucleus. The mass number is equal to the relative atomic mass of the element rounded to an integer. For the mass number, there is a conservation law, which is a special case of the conservation law of a baryon charge.

NEUTRINO
- This is a light (possibly massless) electrically neutral particle, participating only in weak and gravitational interactions. A distinctive feature of neutrinos is its huge penetrating power. It is believed that these particles fill the entire outer space with an average density of about 300 neutrinos per 1 cm3.

NEUTRON
Is an electrically neutral particle having a mass 1839 times the mass of an electron. A free neutron is an unstable particle decaying into a proton and an electron. The neutron is one of the nucleons (along with the proton) and is part of the atomic nucleus.

CONTINUOUS SPECTRUM (continuous spectrum)
- this is a spectrum containing a continuous sequence of all frequencies (or wavelengths) of electromagnetic radiation, smoothly passing into each other. The continuous spectrum is provided by red-hot solids, luminous liquids, dense gases, and also high-temperature plasma. In the optical region, when the light from these bodies is decomposed using a spectral apparatus (spectroscope or spectrograph), the continuous spectrum is represented as a rainbow-colored band in which seven primary colors can be distinguished (red, orange, yellow, green, blue, blue and violet), seamlessly blending into each other. The frequency distribution of energy in the continuous emission spectrum of various bodies is different.

NUCLEOSYNTHESIS
Is a sequence of nuclear reactions leading to the formation of increasingly heavier atomic nuclei from other, lighter ones.

Nucleons
Is a generic name for protons and neutrons - the particles from which atomic nuclei are built.

PRIMARY CONDITION
Is the state of an atom, molecule, or some other quantum system with the smallest possible value of internal energy. Unlike excited states, the ground state is stable.

HALF LIFE
- this is the period of time during which the initial number of radioactive nuclei on average decreases by half. For different elements, it can take values \u200b\u200bfrom many billions of years to fractions of a second. For each type of nucleus, the half-life is a strictly constant value. Experiments with radioactive substances showed that no external conditions (heating to high temperatures, high pressures, etc.) can affect the nature and rate of decay.

POSITRON
- an elementary particle with a positive charge equal to the charge of an electron, with a mass equal to the mass of an electron. It is an antiparticle in relation to an electron.

STRIPED SPECTRA
Are optical spectra of molecules and crystals, consisting of wide spectral bands, the position of which is different for different substances.

POSTULATES OF BOR
- these are the basic principles of the "old" quantum theory - the theory of the atom, developed in 1913 by the Danish physicist Bohr.
Bohr's first postulate: an atom may not be in all states allowed by classical physics, but only in special quantum (or stationary) states, each of which corresponds to a certain energy; in a stationary state, the atom does not emit.
The second postulate of Bohr: during the transition of an atom from one stationary state to another, a quantum of electromagnetic radiation is emitted or absorbed. The energy of a quantum (photon) emitted or absorbed in this case is equal to the difference in energy between stationary states.

PROTON
- it is a positively charged elementary particle having a mass exceeding the mass of an electron by 1836 times; the nucleus of a hydrogen atom. The proton (along with the neutron) is one of the nucleons and is part of the atomic nuclei of all chemical elements.

EXIT WORK
- the minimum work that must be done to remove an electron from a solid or liquid substance in a vacuum. The work function is determined by the nature of the substance and the state of its surface.

RADIOACTIVITY
- this is the ability of some atomic nuclei to spontaneously turn into other nuclei, while emitting various particles: Any spontaneous radioactive decay is exothermic, that is, it occurs with the release of heat.

STRONG INTERACTION
- This is one of the four fundamental interactions of elementary particles, of which nuclear forces are a particular manifestation. Compared to other types of interactions is the most intense. It has a short-range character: its radius of action is only 10-15 m. A strong interaction is characteristic of particles called hadrons. The carriers of strong interaction are gluons.

WEAK INTERACTION
- This is one of the four fundamental interactions of elementary particles, a particular manifestation of which is beta decay of atomic nuclei. Weak interaction is less intense than strong and electromagnetic interactions, but much stronger than gravitational. Weak interaction is characteristic of almost all particles, but its radius of action is extremely small: ~ 10–18 m. The intermediate bosons are carriers of weak interaction.

RATIO OF UNCERTAINTY
- this is the fundamental relationship of quantum mechanics, according to which the product of uncertainties ("inaccuracies") in the coordinate and the corresponding projection of the particle momentum for any accuracy of their simultaneous measurement cannot be less than half the Planck constant. From the uncertainty relation it follows that the more accurately the location of a particle is determined, the less accurate is the information about its momentum, and vice versa.

RADIATION SPECTRUM
- a set of frequencies or wavelengths contained in the radiation of a given substance.

Absorption Spectrum
- a set of frequencies (or wavelengths) of electromagnetic radiation absorbed by a given substance.

SPECTRAL ANALYSIS
Is a method for determining the chemical composition of a substance from its spectrum. A distinction is made between qualitative spectral analysis, with the help of which it is established which chemical elements are included in the composition of a substance, and quantitative spectral analysis, which makes it possible to determine its quantitative content in the sample by the intensity of the spectral lines of a chemical element.

SPIN
Is the intrinsic angular momentum of an elementary particle. It has a quantum nature and (unlike the angular momentum of ordinary bodies) is not associated with the motion of a particle as a whole.

HEAT RADIATION
- This is electromagnetic radiation arising from the internal energy of the substance emitting it. It is characterized by a continuous (continuous) spectrum with a maximum whose position depends on the temperature of the substance. With its increase, the total energy of thermal radiation increases, and the maximum moves to the region of higher frequencies.

THERMONUCLEAR REACTIONS
- These are nuclear reactions between light atomic nuclei that occur at very high temperatures (~ 108 K and above). In this case, the substance is in a state of fully ionized plasma. The need for high temperatures is explained by the fact that for fusion of nuclei in a thermonuclear reaction it is necessary that they come close to a very small distance and fall within the scope of nuclear forces. This approach is prevented by the Coulomb repulsive forces acting between the nuclei of the same charge. To overcome them, the nuclei must have very high kinetic energy. After the onset of the thermonuclear reaction, all the energy spent on heating the mixture is compensated by the energy released during the course of the reaction.

TRACK
Is the trace left by a charged particle in the detector.

TRITIUM
Is a superheavy radioactive isotope of hydrogen with a mass number of 3. The average tritium content in natural waters is 1 atom per 1018 hydrogen atoms.

Einstein equation for photo effect
Is an equation expressing the relationship between the energy of a photon participating in a photoelectric effect, the maximum kinetic energy of an electron emitted from a substance, and the characteristic of the metal on which the photoelectric effect is observed, is the work function for the metal.

PHOTON
Is an elementary particle, which is a quantum of electromagnetic radiation (in the narrow sense - light). It is a truly neutral particle (i.e., it does not have any charges). It always spreads with a fundamental speed of 3 × 108 meters per second. The photon energy is proportional to the frequency of the oscillations of the tension electric field  radiation, the coefficient of proportionality is a fundamental constant called the Planck constant.

PHOTO EFFECT (external photo effect)
- This is the emission of electrons by bodies under the influence of light.

CHEMICAL ACTIONS OF LIGHT
- these are the actions of light, as a result of which chemical transformations - photochemical reactions - occur in substances that absorb light. The chemical actions of light include photosynthesis reactions in the green parts of plants; the appearance of a tan; tissue fading in the sun; decomposition into components of silver bromide molecules in the photosensitive layer of the photographic plate, etc.
Photochemical transformations play a large role in the mechanism of vision of humans and animals. The role of light in photochemical processes is to impart so much energy to a molecule of a substance that the molecule is split into its constituent parts. The chemical action of light is a quantum phenomenon. As in the case of the photoelectric effect, there is a red border for each photochemical reaction, i.e., the minimum frequency at which light is still chemically active. The existence of such a boundary can be explained only from the standpoint of quantum representations.

CHAIN \u200b\u200bREACTION
- This is a self-sustaining fission reaction of heavy nuclei in which neutrons are continuously reproduced, fissioning more and more new nuclei.

BLACK HOLE
- This is a region of space in which there is such a strong gravitational field that even light cannot leave this region and go to infinity.

ELEMENTARY PARTICLES
Is the conventional name for a large group of micro-objects that are not atoms or atomic nuclei (with the exception of the proton - the nucleus of a hydrogen atom).
At present, about 400 such particles have been discovered (together with antiparticles). Most of them do not satisfy the strict definition of elementarity (indecomposability into even “smaller” formations), since according to modern concepts they (in particular, proton and neutron) are composite systems. For this reason, instead of the term "elementary", the name "subnuclear particles" is sometimes used. Those particles that claim to be the primary elements of matter are called truly elementary or fundamental particles. Fundamental at the present time are leptons (for example, an electron), quarks and interaction carriers (photon, graviton, gluons and intermediate bosons). In contrast, all hadrons (which include mesons and baryons, including nucleons) are composite objects built from smaller particles called quarks.
Individual elementary particles differ in their mass, average lifetime, electric charge  and other characteristics. One of the most fundamental properties of elementary particles is their interconvertibility. Particles formed as a result of various interactions are not included in the composition of the initial particles, but are born directly in the processes of their collisions or decays.

ENERGY EXIT OF NUCLEAR REACTION (reaction energy)
- this is the difference between the kinetic energies of the final and initial state of the particles participating in the nuclear reaction. To find the energy released in the nuclear reaction, it is necessary to subtract the mass of products from the mass of the initial components and multiply by the square of the speed of light.

ATOMIC LINK COMMUNICATION ENERGY
- this is the minimum energy that is necessary for the complete fission of the nucleus into individual nucleons. When a nucleus is formed from nucleons, a decrease in the energy of the nucleus occurs, which is accompanied by a decrease in mass, i.e., the mass of the nucleus must be less than the sum of the masses of the individual nucleons forming this nucleus. The difference between the sum of the masses of nucleons (protons and neutrons) and the mass of the nucleus consisting of them, multiplied by the square of the speed of light in vacuum, is the binding energy of the nucleons in the nucleus. The binding energy per nucleon is called the specific binding energy.

COMPON EFFECT
- this is a decrease in the frequency of electromagnetic radiation when it is scattered by free electrons. It is observed for high frequencies of scattered radiation (in the x-ray region and above). The Compton effect reveals the quantum properties of electromagnetic radiation. The correct explanation of the effect was given on the basis of the idea that electromagnetic radiation is a stream of photons with energy and momentum associated with the radiation frequency.

NUCLEAR (PLANETARY) ATOM MODEL
- A model of the structure of the atom proposed by the British physicist Rutherford, according to which the atom is as empty as the solar system. In the center of an atom is a nucleus that is positively charged, and almost the entire mass of the atom is concentrated in it. The nucleus of an element with ordinal Z carries a charge that is Z times greater than the elementary one, has dimensions tens of thousands of times smaller than the size of the entire atom. Z electrons circulate around the nucleus under the influence of Coulomb electric forces, so that the whole atom is neutral.

NUCLEAR REACTIONS
- This is the transformation of atomic nuclei as a result of interaction with each other or with any elementary particles. To carry out a nuclear reaction, it is necessary that the colliding particles approach a distance of the order of 10–15 m. Nuclear reactions obey the laws of conservation of energy, momentum, electric and baryonic charges. Nuclear reactions can occur both with the release and absorption of kinetic energy, and this energy is approximately 106 times higher than the energy absorbed or released during chemical reactions.

NUCLEAR FORCES
Is a measure of the interaction of nucleons in an atomic nucleus. It is these forces that hold the protons of the same name charged in the nucleus, preventing them from scattering under the influence of electric repulsive forces. Nuclear forces have a number of specific properties:
1. Nuclear forces are 2–3 orders of magnitude more intense than electromagnetic ones.
2. Nuclear forces have a short-range character: their radius of action is R ~ 10–15 m (that is, they coincide in order of magnitude with the radius of the atomic nucleus).
3. Nuclear forces are attractive forces at distances of ~ 10–15 m, but at substantially shorter distances between nucleons they transform into repulsive forces.
4. Nuclear forces are off-center; in the classical (non-quantum) language, this means that they are directed at a certain angle to the straight line connecting the interacting particles (forces of this type are called tensor forces).
5. Nuclear forces have charge independence, that is, the forces acting between a neutron and a neutron, between a proton and a proton, and also between a neutron and a proton, are the same.
6. Nuclear forces have the property of saturation: each nucleon in the nucleus attracts only a small number of its neighbors, while repelling the remaining particles.
7. Along with conventional (paired) nuclear forces, there are so-called triple (and generally multiparticle) nuclear forces whose radius of action is approximately half that of conventional paired forces. (By triple we mean forces between three particles that vanish when at least one of these particles moves to infinity.)
8. Nuclear forces, at least in part, are exchangeable. According to the meson theory of nuclear forces, the interaction between nucleons is carried out by the emission and absorption by these particles of quanta of a special pion field - pi mesons. A complete complete theory of nuclear forces, which would explain and predict all their properties, has not yet been created.

NUCLEAR PHOTO EMULSIONS
- These are emulsions used to record tracks of charged particles. In the study of high-energy particles, these emulsions are stacked in stacks of several hundred layers. A charged particle passing through them excites atoms encountered on the path, leading to the formation of a latent image in the emulsion. After development, the track becomes visible. Due to the large inhibitory ability of emulsions, the tracks are short. So, for example, in a typical photoemulsion, α-particles with an energy of 55 MV leave a track with a length of about 1 mm. Therefore, the traces left in the emulsions are observed using microscopes, giving an increase of 200 to 2000 times.

NUCLEAR REACTOR
Is a device in which a controlled chain reaction of fission of nuclei is carried out. The main part of a nuclear reactor is the core, in which a chain reaction takes place and nuclear energy is released. The chain reaction is controlled by special control rods, which are introduced into the reactor core using a remote control panel. These rods are made of materials that strongly absorb neutrons (cadmium or boron). The parameters of the active zone are calculated so that, with the rods fully inserted, the chain reaction certainly does not occur. The reactor begins to work when the rods are extended so that the neutron multiplication factor is equal to 1.

Nucleus (atomic)
- This is the positively charged central part of the atom, in which 99.96% of its mass is concentrated. The radius of the nucleus is ~ 10–15 m, which is approximately one hundred thousand times smaller than the radius of the entire atom, determined by the size of its electron shell.
The atomic nucleus consists of protons and neutrons. Their total number in the core is denoted by the letter A and is called the mass number. The number of protons in the nucleus Z determines the electric charge of the nucleus and coincides with the atomic number of the element in the periodic system of elements of D. I. Mendeleev. The number of neutrons in a nucleus can be defined as the difference between the mass number of a nucleus and the number of protons in it. Mass number is the number of nucleons in the nucleus.
Nucleons in the nucleus are held by special nuclear forces, which are a particular manifestation of the so-called strong interaction. The powerful nuclear forces operating in the nucleus ensure its stability. A measure of the stability of a nucleus is its binding energy.

State vector- a value that completely describes the state of a microobject (electron, proton, atom, molecule) and generally any closed quantum system.

In quantum theory, the state vector is usually denoted by | \u003e. If some data set defining the system is denoted by the letter xthen the state vector will have the form | x>.

Wave function(WF) is a special case, one of the possible forms of representing the state vector as a function of coordinates and time or the variables associated with it. This is a representation of the system, as close as possible to the usual classical description, which assumes the existence of a common space-time independent of anything.

The description of the state of a micro-object using the WF is statistical, that is, probabilistic: the square of the absolute value (module) of the WF indicates the value of the probabilities of those quantities on which the WF depends. For example, if the dependence of the particle WF on coordinates is given x, at, z  and time t, then the square of the modulus of this WF determines the probability of detecting a particle at the moment t  at the point with coordinates x, at, z. Since the probability of the state is determined by the square of the WF, it is also called the probability amplitude.

Harmonic oscillator  (GO) - a physical system that performs harmonic oscillations around a stable equilibrium position. For GO, the potential energy of the system U is determined by the expression, where x  - deviation of the system from the equilibrium position; k  is a constant coefficient. For a harmonic oscillator, the average kinetic energy of the system over the period of oscillations is exactly equal to the average potential energy.

A quantum oscillator is characterized by a discrete set of states, energy levels Enwhich are located at equal distances   where n \u003d 0, 1, 2 ...; h  - Planck's constant; ? - natural frequency of oscillations.

Hilbert space(GP) - as applied to the problems of quantum mechanics, this is the space of possible states of the system, defined by a set of eigen (basic, or ground) states.

GP elements must have convergence properties (that is, consist of vectors whose “length” is finite) for which the notion of proximity between objects is established in a certain way.

A significant role in the GP is played by operators. The operator defined in the GP acts on one element of the GP and transfers it to another.

Depending on the task, we can choose one or another set of basis states. If we are interested in the spatial coordinates of the particle, then an infinite-dimensional Hilbert space is chosen, since the coordinate is a continuous quantity, and a separate state of the particle is associated with each point in space. If we are interested in the behavior of the particle’s spin, we can choose the spin states possible for the particle, for example, “spin-up” and “spin-down” as a basis.

Decoherence- a physical process that is accompanied by a decrease in quantum entanglement as a result of the interaction of the system with the environment. Decoherence is accompanied by the appearance of classical features in it: subsystems “manifest” from a nonlocal state, acquiring visible local forms. This process can be described as the formation of quantum correlations (or entanglement, entanglement) between the system and its environment, arising in the process of their interaction. In this sense, decoherence is identical to quantum measurement.

Decoherence, due to the interaction of a quantum system with its environment, destroys quantum effects, turning them into classical ones. Because of this interaction, there is a "confusion" of the states of the system with such a large number of environmental conditions that coherent effects are "lost" during the averaging and become unobservable.

Decoherence is a movement from the source, the center, to the periphery, to a multitude of outwardly unconnected phenomena. A fully decoded system is moving toward chaos.

As applied to the human psyche, decoherence means a narrowing of attention on one side of a phenomenon, an object of attraction or addiction, as a result of which a person finds himself in a narrowed space of perception. He accepts one side of the phenomenon, but not the other.

Diffraction- scattering of microparticles (electrons, neutrons, atoms, etc.) by crystals or molecules of liquids and gases, in which deflected beams are formed from the initial particle beam, the direction and intensity of which depend on the structure of the scattering object.

Particle diffraction occurs due to the interference of components formed by the interaction of the initial beam with the periodic structure of the object and can be understood only on the basis of quantum theory. Particle diffraction, from the point of view of classical physics, is impossible.

Diffraction of light- a phenomenon observed when light propagates past the sharp edges of various bodies (for example, cracks). In this case, the straightness of light propagation is violated, that is, a deviation from the laws of geometric optics.

Entangled (quantum-correlated) states(ZS) - a form of correlation of composite systems that does not have a classical analogue. ZS - the state of a composite system that cannot be divided into separate, completely independent and independent parts, that is, it is an inseparable (inseparable) state. ZS can arise in the system, the parts of which interacted, and then the system broke up into subsystems that do not interact with each other. For such systems, the fluctuations of the individual parts are interconnected through nonlocal quantum correlations, when a change in one part of the system at the same moment in time affects the rest of its parts (even separated in space at infinitely large distances).

In the case of open systems interacting with the environment, the connection between the particles will remain until the superposition of states turns into a mixture under the influence of interaction with surrounding objects.

Interference- addition in space of two (or several) waves, at which amplification or attenuation of the amplitude of the resulting wave is obtained at different points. If the crests of one wave coincide in the crests of another wave, then amplification occurs, and the amplitude increases. If the crests of one wave fall into the hollows of another, then the waves cancel each other out, and the amplitude of the resulting wave weakens.

Interference is characteristic of all waves, regardless of their nature: for waves on the surface of a liquid, elastic (for example, sound) waves, electromagnetic (for example, radio waves or light) waves.

Quantum system  - This term does not indicate the size of the system, but the way it is described by the methods of quantum physics in terms of states.

Classic correlations- the relationship of the characteristics of any objects through ordinary interactions through the exchange of energy. The rate of establishment of classical correlations between objects is limited by the speed of light.

Coherence(from lat. cohaerens  - in communication) is the coordinated flow of several vibrational or wave processes in time, which manifests itself when they are added. Oscillations are called coherent if the phase difference remains constant in time and determines the amplitude of the total oscillation when the oscillations are added.

Correlation(from lat. correlatio - interdependence) - a systematic and conditional relationship between two data series.

Density matrix  - matrix (table of elements), with the help of which both pure-quantum states and mixed states arising from the interaction of the system with the environment are described.

Nonlocality- a property of entangled states that cannot be compared with local elements of reality. The term "non-locality" is often used to describe the non-spatial relationship of entangled states when one particle or part of a system immediately responds to changes with another particle or subsystem, regardless of the distance between them.

Uncertainties ratio(the uncertainty principle) is one of the principles of quantum theory, which states that any physical system cannot be in states in which the coordinates of its center of inertia and momentum simultaneously take exact values. The equivalent formulation is that for any system, energy can be measured with an accuracy not exceeding where h  - Planck's constant; ? t  - measurement time. In other words, the classical concepts of coordinate and momentum are applicable to microparticles only within the limits established by the Heisenberg relations. Thus, the law of conservation of energy during small periods of time may not be fulfilled, this makes it possible to create virtual particles (or pairs) that exist for a short time. According to quantum field theory, any interaction can be represented as a set of processes involving virtual particles.

Inseparability- the fundamental impossibility to divide the system into separate and independent from each other components. Same as quantum entanglement.

Light polarization- the property of optical radiation, consisting in the inequality of different directions in the plane perpendicular to the light beam (the direction of propagation of the light wave). This is due to the fact that the electric field vectors oscillating in a light wave E  and tension magnetic field N  perpendicular to the direction of wave propagation and emit certain directions in space.

Energy flowcharacterizes the intensity of energy exchange of an object with its surroundings. The energy flux density is the amount of energy flowing per unit time through a unit surface area perpendicular to the flow. The energy flows inside the body arise due to the uneven distribution of energy, that is, due to the presence of energy gradients that arise, for example, during accelerations. In relation to our perception, this is felt as “breathtaking”, “blood rushed to the head”, “hair stirred” or a soft feeling of what is happening in the body.

Scattering- the process of interaction of microparticles with various objects (including other particles), during which their energy, direction of motion, internal state, etc. can change.

Recoherence- the process opposite to decoherence, that is, the transition from mixed (classical) states to pure quantum ones. This is the process of acquiring a system of quantum properties, including quantum entanglement, upon termination or weakening of interaction with the environment. To regenerate the system into a quantum state, it is necessary to terminate or weaken the exchange of information with the environment.

In the course of regeneration, dense material shells “blur”, and the boundaries between bodies begin to disappear, and the subsystems are united into a single nonlocal quantum system. Recoherence means movement from the periphery of flickering phenomena to the center, to their source.

Regarding the human psyche, regeneration means awareness, synthesis, getting into the source, that is, a transition to understanding what comes from a wider range of perceptions of the world. For regeneration, it is necessary to be able to distinguish a fairly complete set of states of a certain event space and be able to interact with them in a controlled manner.

In this case, regeneration is reduced to defocusing attention, that is, removing the focus of attention from an object, thought or feeling that caused addiction without suppressing it.

In subjective perception, regeneration can be characterized by a state of peace, clarity, non-employment, an expanded vision of what is happening. In the case of “recognection” of domestic turmoil, the result can be expressed by the words: “This question does not concern me anymore”; “I noticed so many new and interesting things around”; “It turned out, everything is very good”; “I clearly understood what to do.”

Mixed state- a state of the system that cannot be described by a single state vector, it can only be represented by a density matrix. In a mixed state, the maximum complete set of independent physical quantities that determine the state of the system is not specified, but only the probabilities are determined w1, w2 ... detect the system in various quantum states described by state vectors | 1\u003e, | 2\u003e ...

State of the system- the implementation of the potential under given conditions of one or other potential capabilities of the system. It is characterized by a set of quantities that can be measured.

Clean condition  (pure quantum state) is a state that can be described by a state vector. Pure states describe closed systems.

Physical terms

Acoustics  (from Greek akustikos  - auditory) - in the broad sense - a section of physics that studies elastic waves from the lowest frequencies to the highest (1012–1013 Hz); in the narrow sense, the doctrine of sound. General and theoretical acoustics study the laws of emission and propagation of elastic waves in various media, as well as their interactions with the medium. Acoustics sections include electroacoustics, architectural acoustics and building acoustics, atmospheric acoustics, geoacoustics, hydroacoustics, physics and ultrasound techniques, psychological and physiological acoustics, musical acoustics.

Astrospectroscopy- A section of astronomy that studies the spectra of celestial bodies in order to determine the spectral characteristics of the physical and chemical properties of these bodies, including their velocities.

Astrophysics- A branch of astronomy that studies the physical state and chemical composition of celestial bodies and their systems, interstellar and intergalactic media, as well as the processes occurring in them. The main sections of astrophysics: physics of planets and their satellites, physics of the Sun, physics of stellar atmospheres, interstellar medium, theory of the internal structure of stars and their evolution. Relativistic astrophysics considers the problems of the structure of superdense objects and related processes (capture of matter from the environment, accretion disks, etc.) and the tasks of cosmology.

Atom  (from Greek atomos - indivisible) - the smallest particle of a chemical element that preserves its properties. At the center of the atom is a positively charged nucleus, in which almost the entire mass of the atom is concentrated; the electrons moving around form electron shells whose dimensions (~ 108 cm) determine the size of the atom. The nucleus of an atom consists of protons and neutrons. The number of electrons in an atom is equal to the number of protons in the nucleus (the charge of all electrons in the atom is equal to the charge of the nucleus), the number of protons is equal to the ordinal number of the element in the periodic system. Atoms can attach or donate electrons, becoming negatively or positively charged ions. Chemical properties  atoms are determined mainly by the number of electrons in the outer shell; connecting chemically, atoms form molecules. An important characteristic of an atom is its internal energy, which can only take on certain (discrete) values \u200b\u200bcorresponding to stable states of the atom, and changes only stepwise by a quantum transition. Absorbing a certain portion of energy, the atom goes into an excited state (to a higher energy level). From an excited state, an atom emitting a photon can go into a state with lower energy (to a lower energy level). The level corresponding to the minimum energy of the atom is called the main, the rest - excited. Quantum transitions determine the atomic absorption and emission spectra that are individual for the atoms of all chemical elements.

Atomic massIs the mass of an atom, expressed in atomic units of mass. Atomic mass is less than the sum of the masses that make up an atom of particles (protons, neutrons, electrons) by an amount due to the energy of their interaction.

Atomic nucleus- the positively charged central part of the atom, in which the entire mass of the atom is practically concentrated. Consists of protons and neutrons (nucleons). The number of protons determines the electric charge of the atomic nucleus and the atomic number Z of the atom in the Periodic system of elements. The number of neutrons is equal to the difference between the mass number and the number of protons. The volume of the atomic nucleus varies in proportion to the number of nucleons in the nucleus. In diameter, heavy atomic nuclei reach 10-12 cm. The density of nuclear matter is about 1014 g / cm3.

Aerolite- The outdated name of a stone meteorite.

White dwarfs- compact star-shaped remnants of the evolution of low-mass stars. These objects are characterized by masses comparable to the mass of the Sun (2 1030 kg); radii comparable to the radius of the Earth (6400 km) and densities of the order of 106 g / cm3. The name “white dwarfs” is associated with small sizes (compared with the typical sizes of stars) and the white color of the first open objects of this type, determined by their high temperature.

Block  - a part in the form of a wheel with a groove around the circumference for a thread, chain, rope. They are used in machines and mechanisms to change the direction of action of a force (fixed block), to obtain a gain in force or path (moving block).

Car- A large and exceptionally bright meteor.

Vacuum  (from lat. vacuum  - void) is the state of the gas at pressures p lower than atmospheric. Distinguish between low vacuum (in vacuum devices and installations it corresponds to a pressure region p above 100 Pa), medium (0.1 Pa< p < 100 Па), высокий (10-5 Па < p < 0,1 Па), и сверхвысокий (p < 10-5 Па). Понятие «вакуум» применимо к газу в откаченном объеме и в свободном пространстве, напр. к космосу.

Rotating moment  - a measure of external influence, changing the angular velocity of a rotating body. Torque Mbp is equal to the sum of the moments of all the forces acting on the body relative to the axis of rotation and is related to the angular acceleration of the body e by the equality MvR = Ie where I  - moment of inertia of the body relative to the axis of rotation.

Universe- the entire existing material world, unlimited in time and space and infinitely diverse in the forms that matter takes in the process of its development. The Universe studied by astronomy is a part of the material world that is accessible to research by astronomical means corresponding to the achieved level of development of science (sometimes this part of the Universe is called the Metagalaxy).

Computer Engineering – 1 ) a set of technical and mathematical tools (computers, devices, devices, programs, etc.) used to mechanize and automate the processes of computing and information processing. It is used in solving scientific and engineering problems associated with a large amount of computation in automatic and automated control systems, in accounting, planning, forecasting and economic evaluation, for making scientifically sound decisions, processing experimental data, in information retrieval systems, etc. . 2 ) A branch of technology engaged in the development, manufacture and operation of computers, devices and instruments.

Gas  (French gaz, from Greek. chaos  - chaos) - the state of aggregation of a substance in which kinetic energy thermal motion of its particles (molecules, atoms, ions) significantly exceeds the potential energy of the interactions between them, and therefore, the particles move freely, uniformly filling in the absence of external fields the entire volume provided to them.

Galaxy  (from Greek galaktikos  - milky) - the star system (spiral galaxy) to which the sun belongs. The galaxy contains at least 1011 stars (with a total mass of 1011 solar masses), interstellar matter (gas and dust, whose mass is several percent of the mass of all stars), cosmic rays, magnetic fields, radiation (photons). Most stars occupy a lenticular volume with a diameter of approx. 30 thousand pc, concentrating to the plane of symmetry of this volume (galactic plane) and to the center (flat subsystem of the Galaxy). A smaller part of the stars fills an almost spherical volume with a radius of approx. 15 thousand pc (spherical subsystem of the Galaxy), concentrating to the center (core) of the Galaxy, which is located from the Earth in the direction of the constellation Sagittarius. The sun is located near the galactic plane at a distance of approx. 10 thousand pc from the center of the Galaxy. For the earth observer, stars concentrating on the galactic plane merge into the visible picture of the Milky Way.

Helium  (lat. Helium) Is a chemical element with atomic number 2, atomic mass of 4.002602. Refers to the group of inert, or noble, gases (group VIIIA of the periodic system).

Hyperons  (from Greek hypér –   over, above) –   heavy unstable elementary particles with a mass greater than the mass of the nucleon (proton and neutron), which have a baryon charge and a longer lifetime compared to “nuclear time” (~ 10-23   sec).

Gyroscope  (from gyro... and ... osprey) Is a rapidly rotating solid whose axis of rotation can change its direction in space. The gyroscope has a number of interesting properties observed in rotating celestial bodies, in artillery shells, in a baby gyroscope, in turbine rotors installed on ships, etc. Various gyroscopes are based on the properties of the gyroscope, which are widely used in modern technology for automatic control of aircraft , ships, missiles, torpedoes and other objects, to determine the horizon or geographical meridian, to measure the translational or angular velocities of moving objects (e.g. missiles) and many oh dr

Globules- gas and dust formations measuring several tenths of a parsec; observed as dark spots against a background of bright nebulae. Perhaps globules are areas of star birth.

Gravity field  (gravitational field) - a physical field created by any physical objects; through the gravitational field is the gravitational interaction of bodies.

Pressure  - a physical quantity characterizing the intensity of normal (perpendicular to the surface) forces F with which one body acts on the surface S of another (for example, the foundation of a building on the ground, liquid on the walls of the vessel, etc.). If the forces are uniformly distributed along the surface, then the pressure is P \u003d F / S. Pressure is measured in Pa or in kgf / cm2 (the same as at), as well as in mmHg. Art., atm, etc.

Dynamics  (from Greek. dynamis - force) is a section of mechanics in which the motion of bodies under the influence of forces applied to them is studied.

Discreteness  (from lat. discretus  - divided, intermittent) - discontinuity; contrasted with continuity. For example, a discrete change in a quantity in time is a change that occurs at certain time intervals (irregularly).

Dissociation  (from lat. dissociatio  - separation) - the decay of a particle (molecule, radical, ion) into several simpler particles. The ratio of the number of particles decaying during dissociation to their total number before decay is called the degree of dissociation. Depending on the nature of the action causing dissociation, thermal dissociation, photodissociation, electrolytic dissociation, dissociation under the influence of ionizing radiation are distinguished.

Inch  (from gol. duim, letters. - thumb) - 1 ) fractional unit of length in the system of English measures. 1 inch \u003d 1/12 feet \u003d 0.0254 m. 2 ) Russian odometric unit of length. 1 inch \u003d 1/12 feet \u003d 10 lines \u003d 2.54 cm.

Liquid  - the state of aggregation of a substance that combines the features of a solid state (preservation of volume, a certain tensile strength) and gaseous (shape variability). A liquid is characterized by a short-range order in the arrangement of particles (molecules, atoms) and a small difference in the kinetic energy of the thermal motion of molecules and their potential interaction energy. The thermal motion of liquid molecules consists of oscillations near equilibrium positions and relatively rare jumps from one equilibrium position to another, fluid fluidity is associated with this.

Law - a necessary, substantial, stable, repeating relationship between phenomena in nature and society. The concept of "law" is related to the concept of essence. There are three main groups of laws: specific, or particular (for example, the law of addition of speeds in mechanics); common to large groups of phenomena (for example, the law of conservation and transformation of energy, the law of natural selection); universal, or universal, laws. Knowledge of the law is the task of science.

Wien's Law of Radiation- establishes the distribution of energy in the spectrum of a black body depending on temperature. A special case of Planck's law of radiation for high frequencies. Bred in 1893 by W. Vin.

Planck's radiation law- establishes the distribution of energy in the spectrum of a black body (equilibrium thermal radiation). Bred by M. Planck in 1900.

Electromagnetic radiation- the process of formation of a free electromagnetic field; radiation is also called the free electromagnetic field itself. Accelerated moving charged particles (e.g., bremsstrahlung, synchrotron radiation, radiation from alternating dipoles, quadrupoles and higher-order multipoles) emit. An atom and other atomic systems emit during quantum transitions from excited states to states with lower energy.

Insulator  (from the French. isoler - disconnect) - 1 ) a substance with a very high electrical resistivity (dielectric). 2 ) A device that prevents the formation of electrical contact and, in many cases, also provides mechanical communication between parts of electrical equipment under different electrical potentials; made of dielectrics in the form of disks, cylinders, etc. 3 ) In radio engineering, insulators are called a segment of a short-circuited 2-wire or coaxial line, which has a large electrical resistance at a given frequency.

Isotopes  (from from... and Greek. topos  - place) - varieties of chemical elements in which the nuclei of atoms differ in the number of neutrons but contain the same number of protons and therefore occupy the same place in the periodic system of elements. There are stable (stable) isotopes and radioactive isotopes. The term was proposed by F. Soddy in 1910.

Pulse – 1 ) measure of mechanical motion (the same as the amount of motion). Impulse is possessed by all forms of matter, including electromagnetic and gravitational fields; 2 ) momentum of force - a measure of the force for a certain period of time; equal to the product of the average value of the force at the time of its action; 3 ) wave impulse - a single disturbance propagating in space or medium, for example: sound impulse - a sudden and rapidly disappearing increase in pressure; light pulse (a special case of electromagnetic) - short-term (0.01 s) light emission by an optical radiation source; 4 ) pulse-electric - a short-term deviation of voltage or current from a certain constant value.

Inertial reference system -  a reference frame in which the law of inertia is valid: a material point, when no forces act on it (or mutually balanced forces act), is at rest or in uniform rectilinear motion.

Jonah  (from Greek ion  - walking) - electrically charged particles formed from an atom (molecule) as a result of the loss or attachment of one or more electrons. Positively charged ions are called cations, negatively charged ions are called anions. The term was proposed by M. Faraday in 1834.

Dwarfs- stars of small sizes (from 1 to 0.01 of the radius of the Sun) and low luminosities (from 1 to 10-4 of the luminosity of the Sun) with a mass M  from 1 to 0.1 solar mass. Among dwarfs there are many eruptive stars. White dwarfs sharply differ in structure and properties from ordinary, or red, dwarfs.

Quantization secondary  - a method for studying quantum systems of many or an infinite number of particles (or quasiparticles); especially important in quantum field theory, considering systems with a varying number of particles. In the quantization method, the secondary state of the system is described using fill numbers. The change in state is interpreted as the processes of birth and destruction of particles.

Quantum mechanics (wave mechanics) Is a theory establishing a description method and laws of microparticle motion in given external fields; one of the main sections of quantum theory. For the first time, quantum mechanics made it possible to describe the structure of atoms and understand their spectra, establish the nature of chemical bonds, explain the periodic system of elements, etc. Since the properties of macroscopic bodies are determined by the motion and interaction of the particles that form them, the laws of quantum mechanics underlie the understanding of most macroscopic phenomena. So, quantum mechanics made it possible to understand many properties of solids, to explain the phenomena of superconductivity, ferromagnetism, superfluidity, and much more; quantum-mechanical laws underlie nuclear power, quantum electronics, etc. Unlike classical theory, all particles act in quantum mechanics  as carriers and corpuscular, and wave propertieswhich do not exclude, but complement each other. The wave nature of electrons, protons and other "particles" is confirmed by experiments on the diffraction of particles. The wave-particle duality of matter required a new approach to the description of the state of physical systems and their changes over time. The state of a quantum system is described by a wave function, the square of the module of which determines the probability of a given state and, therefore, the probability for the values \u200b\u200bof physical quantities that characterize it; it follows from quantum mechanics that not all physical quantities can simultaneously have exact values \u200b\u200b(see the Uncertainties principle). The wave function obeys the superposition principle, which explains, in particular, the diffraction of particles. A distinctive feature of quantum theory is the discreteness of possible values \u200b\u200bfor a number of physical quantities: electron energy in atoms, angular momentum and its projection in an arbitrary direction, etc .; in classical theory, all these quantities can only change continuously. The fundamental role in quantum mechanics is played by the Planck constant ћ - one of the main scales of nature, distinguishing between the areas of phenomena that can be described by classical physics (in these cases, j \u003d 0 can be considered) from the areas for which the quantum theory is necessary for the correct interpretation. Nonrelativistic (referring to low particle velocities compared to the speed of light) quantum mechanics is a complete, logically consistent theory that is fully consistent with experience for the circle of phenomena and processes in which particles are not generated, destroyed or interconverted.

Quantum theory- combines quantum mechanics, quantum statistics and quantum field theory.

Quarks  - hypothetical fundamental particles, of which, according to modern concepts, all hadrons consist of (baryons - of three quarks, mesons - of a quark and antiquark). Quarks have a spin of 1/2, a baryon charge of 1/3, electric charges of -2/3 and +1/3 of the proton charge, as well as a specific quantum number “color”. Experimentally (indirectly), 6 types ("aromas") of quarks were discovered: u, d, s, c, b, t. In a free state were not observed.

Kinetic energy- the energy of a mechanical system, depending on the speeds of its constituent parts. In classical mechanics, the kinetic energy of a mass point of mass mmoving at speed vis 1/2 mv2.

Oxygen  (lat. Ohygenium) Is a chemical element with atomic number 8, atomic mass is 15.9994. In the periodic system of elements, Mendeleev is located in the second period in the VIA group.

Classic mechanics- studies the motion of macroscopic bodies with velocities small compared to the speed of light, based on Newton’s laws.

Fluctuations -  movements (changes in state) with varying degrees of repeatability. When the pendulum oscillates, its deviations are repeated in one direction and the other from the vertical position. With the oscillation of the spring pendulum –   load hanging on a spring, –   deviations of it up and down from a certain middle position are repeated. When oscillating in an electrical circuit having a capacitance C and inductance L, the magnitude and sign of the charge are repeated q  on each capacitor plate. Oscillations of the pendulum occur because: 1) gravity returns the deflected pendulum to the equilibrium position; 2) returning to the equilibrium position, the pendulum, possessing speed, continues to move (by inertia) and again deviates from the equilibrium position in the direction opposite to the one from which it came.

Colorimetry  (from lat. color  - color and buckwheat. metreo  - measure), methods of measurement and quantitative expression of color, based on determining the coordinates of the color in the selected system of 3 primary colors.

Coma- image distortion in optical systems, because of which the point of the object takes the form of an asymmetric spot.

Comets  (from Greek kometes, letters. - long-haired), the bodies of the solar system move in very elongated orbits, at considerable distances from the sun they look like faintly luminous spots of an oval shape, and with approaching the sun they have a “head” and a “tail”. The central part of the head is called the nucleus. The diameter of the core is 0.5-20 km, the mass is 1011-1019 kg, the core is an icy body - a conglomerate of frozen gases and dust particles. The tail of a comet consists of molecules (ions) of gases and dust particles escaping from the nucleus under the action of sunlight, and the length of the tail can reach tens of millions of kilometers. The most famous periodic comets are Halley (period R76 years old), Enke ( R3.3 years), Schwassman - Wachmann (the orbit of the comet lies between the orbits of Jupiter and Saturn). When passing through perihelion in 1986, Halley's comet was investigated by spacecraft.

Compton effect - discovered by A. Compton (1922) elastic scattering of electromagnetic radiation of small wavelengths (x-ray and gamma radiation) by free electrons, accompanied by an increase in wavelength l. The Compton effect contradicts the classical theory that, under such scattering, l should not change. The Compton effect confirmed the validity of quantum ideas about electromagnetic radiation as a flux of photons and can be considered as an elastic collision of two "particles" - a photon and an electron, in which the photon transfers part of its energy (and momentum) to the electron, as a result of which its frequency decreases and l increases .

Convection  (from lat. convectio  - delivery, delivery) - the movement of macroscopic parts of the medium (gas, liquid), leading to the transfer of mass, heat and other physical quantities. Distinguish between natural (free) convection caused by heterogeneity of the medium (temperature and density gradients), and forced convection caused by external mechanical stress on the medium. The formation of clouds is associated with convection in the Earth’s atmosphere, and granulation is associated with convection on the Sun.

Electric circuit  (circuit of an electric circuit) - any closed path passing through several branches of an electric circuit. Sometimes the term "electric circuit" is used as a synonym for the term "oscillating circuit".

Coriolis Strength(named after the French scientist G. Cori-olis) –   one of the inertia forces introduced to take into account the influence of rotation of a moving reference system on the relative motion of a material point. Coriolis force is equal to the product of the mass of a point on its Coriolis acceleration and is directed opposite to this acceleration.

Coefficient  (from lat. co  - jointly and efficiens  - producing) - factor, usually expressed in numbers. If the product contains one or more variables (or unknown) quantities, then the coefficient for them is also called the product of all constants, including those expressed by letters. Many coefficients in physical laws have special names, for example, the coefficient of friction, the coefficient of absorption of light.

Red giants- stars with low effective temperatures (3000-4000 K) and very large radii (10-100 times the radius of the Sun). The maximum radiation energy falls on the red and infrared parts of the spectrum. The luminosity of the red giants is approximately 100 times greater than the luminosity of the Sun.

Lagrange equations -1 ) in hydromechanics - the equations of motion of a liquid medium, written in the Lagrange variables, which are the coordinates of the particles of the medium. From the Lagrange equation, the law of motion of particles of the medium is determined in the form of dependences of coordinates on time, and along them are trajectories, velocities and accelerations of particles. 2 ) In general mechanics - the equations used to study the motion of a mechanical system, in which independent parameters are chosen for the quantities that determine the position of the system, called generalized coordinates. First obtained by J. Lagrange in 1760.

Magnetism  (from Greek magnetis  - magnet) - 1 ) a branch of physics that studies the interaction of moving electrically charged particles (bodies) or particles (bodies) with a magnetic moment, carried out by a magnetic field. 2 ) The general name of the manifestations of this interaction. Magnetic interactions involve elementary particles (electrons, protons, etc.), electric currents and magnetized bodies with a magnetic moment. For elementary particles, the magnetic moment can be spin and orbital. The magnetism of atoms of molecules and macroscopic bodies is determined, ultimately, by the magnetism of elementary particles. Depending on the nature of the interaction of particles carrying magnetic moment, substances may exhibit ferromagnetism, ferrimagnetism, antiferromagnetism, paramagnetism, diamagnetism, and other types of magnetism.

A magnetic field- one of the forms of the electromagnetic field. The magnetic field is created by moving electric charges and spin magnetic moments  atomic carriers of magnetism (electrons, protons, etc.). A complete description of the electric and magnetic fields and their relationship give Maxwell's equations.

Weight  - one of the main physical characteristics of matter, which determines its inert and gravitational properties. In classical mechanics, mass is equal to the ratio of the force acting on the body to the acceleration caused by it (Newton’s 2nd law) - in this case, the mass is called inert; in addition, mass creates a gravitational field - gravitational, or heavy, mass. Inert and heavy masses are equal to each other (equivalence principle).

Mesoatom- an atom-like system in which the forces of electrostatic attraction bind a positive nucleus to one (or several) negatively charged muons (muon atom) or hadrons (hadron atom). Mesoatoms may also contain electrons.

Meteorites- small bodies of the solar system falling on the Earth from interplanetary space. The mass of one of the largest meteors - Goba meteorite - approx. 60 000 kg. Distinguish between iron and stone meteorites.

Method  (from Greek methodos  - research path, theory, teaching) - a way to achieve a goal, solve a specific problem; a set of techniques or operations of practical or theoretical development (cognition) of reality.

Mechanics  (from Greek. mechanike - the art of constructing machines) - the science of the mechanical motion of material bodies (i.e., the change over time of the relative position of bodies or their parts in space) and the interactions between them. At the heart of classical mechanics are Newton's laws. Using the methods of mechanics, we study the movements of any material bodies (except microparticles) with velocities small compared to the speed of light. The motions of bodies with velocities close to the speed of light are considered in relativity of the theory, and the motion of microparticles is considered in quantum mechanics. Depending on the movement of which objects is considered, they distinguish between the mechanics of the material point and the system of material points, mechanics solid body, continuum mechanics. The mechanics are divided into statics, kinematics and dynamics. The laws of mechanics are used to calculate machines, mechanisms, building structures, vehicles, spacecraft, etc. The founders of mechanics are G. Galilei, I. Newton and others.

Microparticles  - particles of very small mass; These include elementary particles, atomic nuclei, atoms, molecules.

Milky Way– 1 ) a luminous strip crossing the starry sky. It represents a huge number of visually indistinguishable stars concentrating on the main plane of the Galaxy. The Sun is located near this plane, so most of the stars of the Galaxy are projected onto the celestial sphere within a narrow strip - the Milky Way. 2 ) Actually the name of the Galaxy.

Molecule  (novolat. moleculawill reduce. from lat. moles  - mass) - a microparticle formed from atoms and capable of independent existence. It has a constant composition of its atomic nuclei and a fixed number of electrons and has a combination of properties that make it possible to distinguish molecules of one kind from molecules of another. The number of atoms in a molecule can be different: from two to hundreds of thousands (eg, in a protein molecule); the composition and arrangement of atoms in the molecule is conveyed by the chemical formula. Molecular structure substances is established by x-ray analysis, electron diffraction, mass spectrometry, electron paramagnetic resonance (EPR), nuclear magnetic resonance (NMR) and other methods.

Molecular mass  (molecular weight) is the mass of a molecule, expressed in atomic units of mass. Almost equal to the sum of the masses of all the atoms that make up the molecule. Quantities molecular weight  used in chemical, physical and chemical-technical calculations.

Moment of inertia- a value that characterizes the distribution of masses in the body and is, along with the mass, a measure of the inertia of the body during unstable movement.

Moment of momentum  (kinetic moment, angular momentum, angular momentum) - a measure of the mechanical motion of a body or system of bodies relative to any center (point) or axis. To calculate the moment of momentum TO  of a material point (body), the same formulas are valid as for calculating the moment of force if we replace the force vector with the momentum vector mv, in particular K0 = [ r× mv]. The sum of the moments of momentum of all points of the system relative to the center (axis) is called the main moment of the momentum of the system (kinetic moment) relative to this center (axis). During the rotational motion of a rigid body, the main moment of momentum relative to the axis of rotation z  body is expressed as the product of the moment of inertia Iz on the angular velocity w of the body, i.e. TOZ \u003d Izw.

Muons  - unstable elementary particles with a spin 1/2, a lifetime of 2.210-6 sec  and a mass approximately 207 times the mass of the electron.

Hadrons  - a class of elementary particles participating in a strong interaction. Everything had to be hadrons baryons  and mesonsincluding resonances.

Hadron Jets  - directional beams of hadrons formed upon the collision of high-energy particles in deeply inelastic processes.

Antiparticles  - particles that differ from similar ones in the sign of electric charge. The names "particle" and "antiparticle" are largely arbitrary.

"Aroma"  - characteristic of quarks, including the entire population quantum numbers  (electric charge, strangeness, “charm”, etc., excluding “color”).

Baryons  - a group of "heavy" elementary particles with a half-integer back  and a mass of not less than the mass of the proton. Protons, neutrons, hyperons, part of resonances, etc. are referred to baryons.

Boson  is a particle with zero and integer spin obeying Bose-Einstein statistics. The bosons include photons, gravitons  (not yet open) mesonsbosonic resonancesgas molecules gluons  and etc.

Vacuum  - a special type of matter, which corresponds to the lowest energy state of quantized fields in quantum field theory. It is characterized by the absence of any real particles, while at the same time it constantly generates short-lived virtual particles.

Virtual particles  - in quantum theory, short-lived particles for which the relationship between energy, momentum and mass is broken: E 2 ≠ p 2 c 2 + m 2 c 2. Virtual particles are carriers of interactions.

Overcharge (Y)  - one of the characteristics of hadrons. The hypercharge is expressed through other quantum numbers of the hadron - baryon charge, strangeness, "charm", "beauty".

Hyperons  - unstable elementary particles with a mass greater than nucleon. Refer to hadrons  and are baryons.

Gluons  - hypothetical, electrically neutral particles, carriers of strong interaction between quarks in quantum chromodynamics. Spin \u003d 1, rest mass \u003d 0.

Goldstone boson  - a hypothetical particle with zero spin and zero mass. Introduced in quantum field theory to distinguish between vacuum states.

Gravity Collapse  - astrophysical process of compression of space objects under the influence of their own gravitational forces.

Graviton  - a quantum of the gravitational field with zero mass and an electric charge, the spin is 2. Gravitons are carriers of the gravitational interaction; not yet experimentally discovered.

Dirac monopol  - a hypothetical particle having one magnetic pole. Its existence was predicted in 1931 by P. Dirac.

Doppler effect  - change in the frequency of oscillations when the source moves in relation to the observer.

Unified Field Theory  - a general theory designed to combine the whole variety of properties of elementary particles and the features of their interaction. Currently, within the framework of the ETF, only electric, magnetic, and weak nuclear interactions have been combined.

Charge parity  - (C-parity), a quantum number characterizing the behavior of neutral particles. In weak interactions, the symmetry associated with charge parity is broken.

Isotopic invariance  - symmetry of strongly interacting particles. On the basis of isotopic invariance, multiplets are formed that allow one to efficiently classify all hadrons.

Instanton  - a special state of vacuum, which corresponds to a strong fluctuation of the gluon field. In the theory of self-organization, instanton is one of the main structures generated by vacuum.

Gauge symmetry - the general name of the class of internal symmetries in quantum field theory and quantum chromodynamics. Gauge symmetries are associated with the properties of elementary particles.

Quasars  - powerful extragalactic sources of electromagnetic radiation. There is an assumption that K. are the active nuclei of distant galaxies.

Quantization of space - time  - the general name of generalizations of quantum field theory based on the hypothesis of the existence of a fundamental length and a fundamental time interval as universal physical constants.

Quantum mechanics  (wave mechanics) is a theory that establishes a description method and laws of motion of microparticles, as well as their relationship with physical quantities directly measured in experiment.

Quantum chromodynamics  (QCD) -quantum field theory of the strong interaction of quarks and gluons, built on the model of quantum electrodynamics based on "color" gauge symmetry.

Quarks  - material particles, of which, according to modern concepts, all hadrons are composed. To understand the dynamics of various processes involving hadrons, six quarks are currently considered sufficient: u, d, s, s, b, t. There is indirect evidence of the existence of the first five quarks.

Quantum numbers  - integer or fractional numbers that determine the possible values \u200b\u200bof the physical quantities characterizing quantum systems. Quantum numbers include: the main (n), orbital (l), magnetic (m e), spin (m s), strangeness, "charm", "beauty", etc.

Chiral symmetry  - in quantum field theory, one of the fundamental dynamic symmetries, through which it becomes possible to have a good description of the processes of hadron scattering and decay at low energies and at very high energies. Enantiomorphisms (right-left) are also referred to chiral symmetry.

K mesons  (kaons) - a group of unstable elementary particles that participate in a strong interaction. The charge asymmetry of the decays K 0 L → π - + e + (μ +) + v e (v μ) and k  0 L → π + + e - (μ -) + v e ˜ (v μ ˜), where the probability of the second decay is 10 ~ "1 more than the first decay" \\ indicates a violation of one of the fundamental symmetries of nature (CP invariance).

Compton wavelength  is the length dimension characteristic of relativistic quantum processes λ 0 \u003d h / mc.

Cosmology  - The doctrine of the Universe as a single whole. The conclusions of cosmology are based on the laws of physics and observational astronomy data, taking into account philosophical principles.

Mesons - unstable elementary particles belonging to hadrons. According to the quark model, M. consists of a quark and an antiquark.

Neutrino  - light (possibly massless) electrically neutral particle with a spin of 1/2. Participates only in weak and gravitational interactions. Neutrinos have enormous penetrating power, and their detection will allow to study in detail the states of the early Universe.

Reversible process  - in thermodynamics and statistical physics, the process of transition of a system from one state to another, allowing the possibility of returning it to its original state.

Time reversal  - The mathematical operation of replacing the sign of time in the equations of motion. Objectively, real time as an attribute of matter is irreversible, and therefore, the operation of replacing the time sign is possible only as an epistemological device that facilitates the solution of a physical problem.

Operators  - in quantum theory, a mathematical symbol used to perform any action on a physical quantity.

Orbital moment  - the angular momentum of the microparticle, due to its motion in a force field with spherical symmetry.

Ground state  quantum system - a steady state with the smallest possible internal energy.

Open systems  - thermodynamic systems that communicate with the environment  matter, energy, momentum. Lately  open systems are studied in chemistry and biology.

Partons  - virtual components of hadrons, manifested in deeply inelastic processes.

Plasma  - one of the main types of matter, is a partially or fully ionized gas. In the plasma state is the vast majority of the universe: stars, galactic nebulae, interstellar medium. In laboratory conditions, plasma is formed in discharges, combustion processes, MHD generators and special installations (for example, Tokamak).

Positron  - (e +) elementary particle with a positive electric charge, numerically equal to the charge of an electron. Is an antiparticle  in relation to the electron.

Vacuum polarization  - a quantum relativistic phenomenon, which consists in the creation of virtual pairs of charged antiparticle particles from a vacuum under the influence of an external field.

Space and time - attributive (inherent) properties of matter. Space expresses the order of coexistence of objects, time - the order of change of events. Space and time are objective, that is, independent of man, and their characteristics are determined solely by the nature of the movement of the corresponding forms of matter.

Proton  - a positively charged elementary particle, the nucleus of a hydrogen atom. It has been suggested that a proton is an unstable particle with a half-life of ~ 10 30 years, however, experimental confirmation of this hypothesis has not yet been implemented.

Pulsars  - variable sources of cosmic electromagnetic radiation.

Resonances  - short-lived excited states of hadrons (life t ~ 10 -22 ÷ 10 -24 s). Unlike other unstable particles, resonances decay mainly due to strong interaction. To date, more than 300 resonances have been discovered.

Relativistic effects - physical phenomenaobserved at speeds comparable to the speed of light. These include: slowing down time, shortening lengths, increasing body weight, etc.

Superconductivity and High Temperature Superconductivity  - property of many conductors, consisting in the fact that their electrical resistance jumps to zero abruptly when cooled to the temperature of liquid hydrogen and helium. At present (March 1987), a transition to the superconducting state of a number of materials at high temperatures has been discovered, which will be of exceptional economic importance.

Symmetry  - a) in physics - a form of proportionality of laws. In a more general sense, symmetry is a type of relationship between two objects that are characterized by both moments of identity and moments of difference. The most widely used in physics are isotopic, "color", gauge, and other symmetries, without which a modern physical theory would be impossible; b) in philosophy, symmetry is one of the general scientific concepts, denoting the formation of moments of identity in different. Symmetry is represented in the objective world in the form of specific forms of symmetry.

Soliton  - structurally stable solitary wave in a nonlinear dispersive (scattering) medium. Solitons are intensively used in the construction of quantum nonlinear field theory.

Compliance principle  - in the methodology of science, one of the principles according to which any subsequent scientific theory should include the previous theory as a limiting (particular) case. With respect to correspondence, for example, Newtonian mechanics and special relativity are found.

Spin - intrinsic moment of the momentum of elementary particles, has a quantum nature, due to the internal "rotation" of the particle.

Spontaneous symmetry breaking  - spontaneous violation of a stable, equilibrium, symmetrical state, provided that the distance from the state with minimal energy. Spontaneous symmetry breaking is associated with the solution of many problems of quantum field theory, including the appearance of particles with zero mass and zero spin.

Supergravity  - gauge theory of supersymmetry, allowing to generalize the general theory of relativity. Within the framework of supergravity, in principle, it is possible to combine all known types of interactions.

Supersymmetry  - symmetry connecting fields whose quanta are bosons with fields whose quanta are farms ions. The most interesting application of supersymmetry is supergravity.

CPT symmetry  - one of the fundamental symmetries, according to which in quantum field theory the equations are invariant with respect to the combined C (charge), P (spatial) and T (time reversal) transformations.

Unitary symmetry  - approximate symmetry inherent in the strong interaction of elementary particles. In electromagnetic and weak interactions it is broken. On the basis of unitary symmetry, it was possible to classify hadrons.

Fluctuations  - random deviations of physical quantities from their average values. Fluctuations occur at any value as a result of random factors.

Fermions  - particles obeying Fermi-Dirac statistics. Fermions have a half-integer spin. Fermions include quarks, leptons (electron, muon, all types of neutrinos).

Photon  - an elementary particle, a quantum of electromagnetic radiation. The rest mass of the photon is zero. Photons belong to bosons.

Parity  - a quantum-mechanical characteristic of the state of a microparticle, reflecting the symmetry properties of the wave function of this particle with respect to spatial transformations.

1.A material point is a body whose dimensions can be neglected when solving specific problems. 2.A reference system is a coordinate system; a reference body with which it is connected and a time measuring device. 3.Displacement is a vector connecting the initial position of the body with the final position of the body4.The trajectory is an imaginary line along which the body moves. 5.Path-path length6.The average speed is the ratio of the entire path traveled at different speeds to the entire travel time. 7.Rectilinear motion-motion along one straight line8.A rectilinear uniform movement is a movement in which a body moving in a straight line at equal intervalstime passes equal distances. 9. The speed with uniform motion is a vector value equal to the ratio of any body movingtime span to this time span. 10. Equally accelerated motion is a movement with constant acceleration. 11.Acceleration-Speed, change in speed. 12.Schedule  Speeds - the dependence of speed on movement time 13. The braking distance is the distance traveled by the body from the start of braking to its complete stop. 14.Strength is a vector quantity, is a quantitative measure of the interaction of bodies. 15.An inertial reference system is a reference system with respect to which the body moves rectilinearly andevenly or rests if no forces act on it. 16. "Newton's First Law": There are reference frames called inertial, with respect to which the body moves uniformly, rectilinearly or rests if the sum of the forces acting on it is zero. 17. "Newton’s Second Law": Acceleration caused by force acting on the body is directly proportional to the force and inversely proportional to body weight 18. "Newton’s Third Law": The reaction force is equal to the force of action 19. The weight of the body is the force with which the body presses on a support or suspension. twenty. Free fall is gravity21. "The Law of Universal Gravity": The force of mutual attraction of two bodies is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. 22. The gravitational constant is a physical quantity equal to the force with which two bodies are attracted, the mass1 kg at a distance of 1 meter. 23. Body momentum is a vector quantity equal to the product of body mass and its speed24. "The law of conservation of momenta": the vector sum of the momenta of the bodies that make up the closed system does not change over time for any interactions of bodies with each other. 25. Inertia is the body’s ability to continue moving after the cessation of the force on it. 26.Mass is a measure of inertia. 27.Mechanical vibrations are any periodically repeated mechanical movements. 28.A period is the time during which the body makes one oscillation. 29.Frequency is a physical quantity equal to the number of oscillations per unit time.. 30.The amplitude of the oscillations is a value equal to the maximum deviation from the equilibrium position. 31.Free vibrations are vibrations caused by an initial deviation from the equilibrium position. 32.Harmonic oscillations are oscillations described by the equation of sine and cosine. 33.Resonance is the phenomenon of a sharp increase in the amplitude of the oscillations of the system when the eigenfrequency coincidesoscillations of the system with the frequency of the external driving force. 34. Waves - Any disturbance propagating in space from the place of occurrence. 35.Elastic waves are perturbations propagated in an elastic medium. 36.Longitudinal waves are waves whose oscillation occurs along the direction of wave propagation.  37. Transverse waves are waves whose oscillation occurs perpendicular to the direction of wave propagation. 38. The wavelength is the distance between the nearest points, oscillating in the same phase.. 39.Sound vibrations are vibrations with a frequency of20 Hz to 20 kHz, which is able to perceive the human ear. 40. Infrasound is an oscillation with a frequency below20 Hz 41. Ultrasound is sound with a frequency above20 kHz 42. Electric current is the ordered movement of charged particles43.Dielectrics are substances that do not conduct electrical current.44.Resistance - A physical quantity characterizing the ability of a substance to conduct electrical  current. 45. "Ohm's Law": The strength of the current in the circuit is directly proportional to the voltage and inversely proportional to the resistance. 46. \u200b\u200bA series connection is a connection in which all elements of a circuit are connected in series with each other. 47. A parallel connection is one in which all circuit elements are connected in parallel to each other. 48. A magnetic field is a special type of matter with which magnetic interactions are carried out. 49.A uniform magnetic field is a field whose lines are parallel  to each other with the same frequency. fifty. An inhomogeneous magnetic field is a field whose lines are curved and located at different frequencies. 51.A solenoid coil, on which a large number of turns of wire with current are wound. 52. “Rule of the Gimlet”: If the direction of translational movement of the Gimlet is the same as the direction of the current in the conductor, then the direction of rotation of the handle of the Gimlet is the same as the direction of the lines of the magnetic field. 53. “Rule of the right hand”: If you grab the solenoid with the palm of your right hand, pointing four fingers in the direction of the current in turns, then the thumb set ninety degrees apart will show the direction of the magnetic field lines inside the solenoid. 54. "The rule of the left hand": If the left hand is positioned so that the lines of the magnetic field enter the palm perpendicular to it, and four fingers are directed to the flow, then the thumb set aside by ninety degrees will show the direction of the force acting on the conductor. 55. Magnetic field induction is a vector quantity characterizing the strength of the magnetic field at each point in space. 56. One Tesla is such an induction of a magnetic field that acts on a conductor one meter long with a current of one Ampere with a force of one Newton. 57. Magnetic flux is a physical quantity that characterizes the change in the vector of magnetic induction passing through a space bounded by a contour. 58. An electromagnetic field is a special type of matter formed from alternating electric and magnetic fields that are mutually incident. 59. "The main point of the theory of Maxell": Any change in the magnetic field leads to the appearance of an alternating electric field, and  any change in the electric field generates an alternating magnetic field. 60. An electromagnetic wave is a system of alternating electric and magnetic fields that generate each other and propagate in space. 61. Ultraviolet radiation is electromagnetic radiation with a shorter wavelength. 62. Light interference is the phenomenon of superposition of two coherent waves, in which an interference pattern is formed. 63. Coherent waves are waves with the same frequency and constant phase difference. 64. The interference picture is a picture of the distribution of the amplitudes of the oscillations in space that does not change with time. 65. Alpha radiation is a stream of helium atom nuclei 66. Betta radiation is a stream of electrons 67. Gamma radiation is a photon flux 68. Radioactivity is the ability of an atom of a substance to spontaneously emit Alpha, Betta and Gamma rays. 69. Alpha decay is the phenomenon of radiation of one or more nuclei of a helium atom. 70. Isotopes are atoms of one substance having a different mass of the nucleus. 71. Nucleons are a generic term for protons and neutrons.