decay level
31subatomic particle — or elementary particle Any of various self contained units of matter or energy. Discovery of the electron in 1897 and of the atomic nucleus in 1911 established that the atom is actually a composite of a cloud of electrons surrounding a tiny but… …
32cosmos — /koz meuhs, mohs/, n., pl. cosmos, cosmoses for 2, 4. 1. the world or universe regarded as an orderly, harmonious system. 2. a complete, orderly, harmonious system. 3. order; harmony. 4. any composite plant of the genus Cosmos, of tropical… …
33radiation — radiational, adj. /ray dee ay sheuhn/, n. 1. Physics. a. the process in which energy is emitted as particles or waves. b. the complete process in which energy is emitted by one body, transmitted through an intervening medium or space, and… …
34Radiocarbon dating — (sometimes simply known as carbon dating) is a radiometric dating method that uses the naturally occurring radioisotope carbon 14 (14C) to estimate the age of carbon bearing materials up to about 58,000 to 62,000 years.[1] Raw, i.e. uncalibrated …
35Synthesizer — For other uses, see Synthesizer (disambiguation). Synth redirects here. For other uses, see Synth (disambiguation). See also: Software synthesizer Early Minimoog by R.A. Moog Inc. (ca. 1970) A synthesizer (often abbreviated synth ) is an… …
36Europe, history of — Introduction history of European peoples and cultures from prehistoric times to the present. Europe is a more ambiguous term than most geographic expressions. Its etymology is doubtful, as is the physical extent of the area it designates.… …
37Background radiation — This article is about ionizing radiation. For microwave background radiation from space, see Cosmic background radiation and cosmic background. Thermal radiation emitted by Earth is not considered in this category because it is not ionizing.… …
38Population inversion — In physics, specifically statistical mechanics, a population inversion occurs when a system (such as a group of atoms or molecules) exists in state with more members in an excited state than in lower energy states. The concept is of fundamental… …
39nutritional disease — Introduction any of the nutrient related diseases and conditions that cause illness in humans. They may include deficiencies or excesses in the diet, obesity and eating disorders, and chronic diseases such as cardiovascular disease,… …
40atom — /at euhm/, n. 1. Physics. a. the smallest component of an element having the chemical properties of the element, consisting of a nucleus containing combinations of neutrons and protons and one or more electrons bound to the nucleus by electrical… …
