chemically pure
81Evolution — Evolution (History and Scientific Foundation) † Catholic Encyclopedia ► Evolution (History and Scientific Foundation) The world of organisms comprises a great system of individual forms generally classified according to structural… …
82Metalloid —   13 14 15 16 17   2  B Boron …
83boron — boronic /boh ron ik, baw , beuh /, adj. /bawr on, bohr /, n. Chem. a nonmetallic element occurring naturally only in combination, as in borax or boric acid, and obtained in either an amorphous or a crystalline form when reduced from its compounds …
84Properties of water — H2O and HOH redirect here. For other uses, see H2O (disambiguation) and HOH (disambiguation). This article is about the physical and chemical properties of pure water. For general discussion and its distribution and importance in life, see Water …
85Glossary of fuel cell terms — The Glossary of fuel cell terms lists the definitions of many terms used within the fuel cell industry. The terms in this glossary may be used by fuel cell industry associations, in education material and fuel cell codes and standards to name but …
86igneous rock — Any of various crystalline or glassy, noncrystalline rocks formed by the cooling and solidification of molten earth material (magma). Igneous rocks comprise one of the three principal classes of rocks, the others being metamorphic and sedimentary …
87Life Sciences — ▪ 2009 Introduction Zoology In 2008 several zoological studies provided new insights into how species life history traits (such as the timing of reproduction or the length of life of adult individuals) are derived in part as responses to… …
88drug use — Introduction use of drugs for psychotropic rather than medical purposes. Among the most common psychotropic drugs are opiates ( opium, morphine, heroin), hallucinogens (LSD, mescaline, psilocybin), barbiturates, cocaine, amphetamines,… …
89Titanium — This article is about the chemical element. For other uses, see Titanium (disambiguation). scandium ← titanium → vanadium …
90Nuclear weapon design — The first nuclear weapons, though large, cumbersome and inefficient, provided the basic design building blocks of all future weapons. Here the Gadget device is prepared for the first nuclear test: Trinity. Nuclear weapon designs are physical,… …
