Toshkent farmatsevtika instituti fizika, matematika va axborot texnologiyalari kafedrasi

Balmer lines:Lines in the spectrum of hydrogen atom in visible range, produced by transition between n 2 and n = 2, n is the principal quantum no.
Bar:A unit of pressure, equal to 105 Pascals.
Baryon:subatomic particle composed of three quarks.
Beat:A phenomenon of the periodic variation in the intensity of sound due to superposition of waves differing slightly in frequency.
Bernoulli's theorem:The total energy per unit volume of a non-viscous, incompressible fluid in a streamline flow remains constant.
Beta particle:An electron emitted from a nucleus in radioactive decay.
Binding energy:The net energy required to decompose a system into its constituent particles.
Black body:An ideal body which would absorb all incident radiation and reflect none.
Black hole:The remaining core of a supernova that is so dense that even light cannot escape.
Boyle's law:For a given mass of a gas at constant temperature, the volume of the gas is inversely proportional to the pressure.
Brewster's law:States that the refractive index of a material is equal to the tangent of the polarizing angle for the material.
Brownian motion:The continuous random motion of solid microscopic particles when suspended in a fluid medium due to the consequence of ongoing bombardment by atoms and molecules.
Bulk's modulus of elasticity:The ratio of normal stress to the volumetric strain produced in a body.
Buoyant force:upward force on an object immersed in fluid.

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Abiogenesis:
The study of how life on Earth could have arisen from inanimate matter. It should not be confused with evolution (the study of how living things change over time), biogenesis (the process of lifeforms producing other lifeforms) or spontaneous generation (the obsolete theory of complex life originating from inanimate matter on an everyday basis).
Absolute Zero:
The lowest temperature possible, equivalent to -273.15°C (or 0° on the absolute Kelvin scale), at which point atoms cease to move altogether and molecular energy is minimal. The idea that it is impossible, through any physical process, to lower the temperature of a system to zero is known as the Third Law of Thermodynamics.
Accretion Disk:
Diffuse material orbiting around a central body such as a protostar, a young star, a neutron star or a black hole. Gravitycauses the material in the disc to spiral inwards towards the central body with great speed, and the gravitational forcesacting on the material cause the emission of x-rays, radio waves or other electromagnetic radiation (known as quasars).