decay level
71Scintillator — Scintillation crystal surrounded by various scintillation detector assemblies …
72Germany — /jerr meuh nee/, n. a republic in central Europe: after World War II divided into four zones, British, French, U.S., and Soviet, and in 1949 into East Germany and West Germany; East and West Germany were reunited in 1990. 84,068,216; 137,852 sq.… …
73analysis — /euh nal euh sis/, n., pl. analyses / seez /. 1. the separating of any material or abstract entity into its constituent elements (opposed to synthesis). 2. this process as a method of studying the nature of something or of determining its… …
74literature — /lit euhr euh cheuhr, choor , li treuh /, n. 1. writings in which expression and form, in connection with ideas of permanent and universal interest, are characteristic or essential features, as poetry, novels, history, biography, and essays. 2.… …
75quantum mechanics — quantum mechanical, adj. Physics. a theory of the mechanics of atoms, molecules, and other physical systems that are subject to the uncertainty principle. Abbr.: QM Cf. nonrelativistic quantum mechanics, relativistic quantum mechanics. [1920 25]… …
76Egypt, ancient — Introduction civilization in northeastern Africa dating from the 3rd millennium BC. Its many achievements, preserved in its art and monuments, hold a fascination that continues to grow as archaeological finds expose its secrets. This article… …
77plant disease — ▪ plant pathology Introduction an impairment of the normal state of a plant that interrupts or modifies its vital functions. All species of plants, wild and cultivated alike, are subject to disease. Although each species is… …
78Island of stability — The island of stability is a term from nuclear physics that describes the possibility of elements with particularly stable magic numbers of protons and neutrons. This would allow certain isotopes of some transuranic elements to be far more stable …
79Opposition to water fluoridation — refers to activism against the fluoridation of public water supplies. The controversy occurs mainly in English speaking countries, as Continental Europe does not practice water fluoridation, although some continental countries fluoridate salt.… …
80wood — wood1 woodless, adj. /wood/, n. 1. the hard, fibrous substance composing most of the stem and branches of a tree or shrub, and lying beneath the bark; the xylem. 2. the trunks or main stems of trees as suitable for architectural and other… …
