Atomic and quantum physics
The structure of the atom, quanta and photons, spectra, quantum transitions.
Material on this topic
10. Thus the electrons in the atom do not constantly “wind” circles in the field of the central forces of the nucleus, but perform oscillations in this field, in the course of which there occurs a continuous transition o…
17. Since the time of Plato it has been customary to regard as material everything that manifests itself through action.
Гипотеза, объясняющая явления, происходящие в фотоне и его строение.
Autoionisation (field ionisation) , the process by which atoms and molecules of a gas are ionised in strong electric fields.
Radiationless quantum transition , a quantum transition in which the energy of a quantum system (an atom, a molecule, an atomic nucleus and so on) changes not through the absorption or emission of electromagnetic radiati…
White dwarfs , compact stars with masses of the order of the mass of the Sun M ο and radii ≈1% of the radius of the Sun R ο ; they make up 3—10% of the total number of stars in the Galaxy.
Beta decay (β-decay), the spontaneous transformations of a neutron n into a proton p and of a proton into a neutron inside an atomic nucleus (and also the transformation of a free neutron into a proton), accompanied by t…
Beta-spectrometer , an instrument for measuring the energy distribution (the spectrum) of the electrons and positrons emitted in β-decay, and also of conversion electrons and of the electrons produced when gamma, X-ray a…
Establishes how the yield of photoluminescence depends on the wavelength of the exciting light.
Bose gas , (named after the Indian physicist Sh.
Bose liquid , a quantum liquid in which the elementary excitations (quasiparticles) have zero or integer spin and obey Bose—Einstein statistics.
Bohr's postulates, the two fundamental assumptions introduced in 1913 by the Danish physicist N.
Bohr radius , in N. Bohr's theory of the hydrogen atom — the radius of the electron orbit nearest to the nucleus (the proton).
Born approximation , in the theory of the scattering (collision) of particles, consists in calculating the scattering amplitude of microparticles (or the cross-section) in the first order of perturbation theory; it was p…
The Burstein-Moss effect , the shift of the edge of the region of intrinsic absorption of light by a semiconductor towards higher frequencies as the concentration of conduction electrons increases and they fill the condu…
Physical vacuum , in quantum field theory — the lowest energy state of the quantised fields, characterised by the absence of any real particles.