million electron-volts
41annihilation radiation — noun : radiation produced by the mutually annihilating coalescence of an electron and a positron from which two radiation quanta travel in opposite directions with a wavelength corresponding to that of very short gamma rays, being approximately 0 …
42Alpha particle — Alpha particles (named after and denoted by the first letter in the Greek alphabet, α) consist of two protons and two neutrons bound together into a particle identical to a helium nucleus; hence, it can be written as He2+ or 42He2+. They are a… …
43Solar proton event — A Solar proton event occurs when protons emitted by the Sun become accelerated to very high energies either close to the Sun during a solar flare or in interplanetary space by the shocks associated with coronal mass ejections. These high energy… …
44annihilation radiation — Physics. electromagnetic radiation produced by the coalescence and mutual annihilation of a positron and an electron, each pair forming two photons having a minimum energy of 0.5 million electron volts each. [1960 65] * * * …
45megaelectron volt — /meg euh i lek tron/, Physics. See million electron volts. [MEGA + ELECTRON VOLT] * * * …
46element 118 — ▪ chemical element a transuranium element that occupies position 118 in the periodic table (periodic law) and one of the noble gases (noble gas). Element 118 is a synthetic element, and in 1999, scientists at Lawrence Berkeley National… …
47MeV — 1. Mega electron Volt Contributor: CASI 2. Million Electron Volts Contributor: MSFC …
48megaelectron volt — /meg euh i lek tron/, Physics. See million electron volts. [MEGA + ELECTRON VOLT] …
49Anthropic principle — In astrophysics and cosmology, the anthropic principle is the philosophical argument that observations of the physical Universe must be compatible with the conscious life that observes it. Some proponents of the argument reason that it explains… …
50alpha decay — Physics. a radioactive process in which an alpha particle is emitted from the nucleus of an atom, decreasing its atomic number by two. [1935 40] * * * Type of radioactive disintegration (see radioactivity) in which some unstable atomic nuclei… …
