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isotope

(Encyclopedia)CE5 Isotopes of hydrogen isotope īˈsətōp [key], in chemistry and physics, one of two or more atoms having the same atomic number but differing in atomic weight and mass number. The concept of ...

formula weight

(Encyclopedia)formula weight, in chemistry, a quantity computed by multiplying the atomic weight (in atomic mass units) of each element in a formula by the number of atoms of that element present in the formula, an...

Cambridge, University of

(Encyclopedia)Cambridge, University of, at Cambridge, England, one of the oldest English-language universities in the world. Originating in the early 12th cent. (legend places its origin even earlier than that of t...

Buckingham, George Villiers, 2d duke of

(Encyclopedia)Buckingham, George Villiers, 2d duke of, 1628–87, English courtier; son of the 1st duke. Brought up with the royal family and educated at Cambridge, he was a strong royalist in the English civil war...

bohrium

(Encyclopedia)bohrium bôrˈēəm [key], artificially produced radioactive chemical element; symbol Bh; at. no. 107; mass number of most stable isotope 270; m.p., b.p., sp. gr., and valence unknown. Situated in Gro...

nihonium

(Encyclopedia)nihonium nĭhōˈnēəm [key], artificially produced radioactive chemical element; symbol Nh; at. no. 113; mass number of most stable isotope 284; m.p., b.p., sp. gr., and valence unknown. Situated in...

poison

(Encyclopedia)poison, any agent that may produce chemically an injurious or deadly effect when introduced into the body in sufficient quantity. Some poisons can be deadly in minute quantities, others only if relati...

butter

(Encyclopedia)butter, dairy product obtained by churning the fat from milk until it solidifies. In most areas the milk of cows is the basis, but elsewhere that of goats, sheep, and mares has been used. Butter was k...

Edison, Thomas Alva

(Encyclopedia)Edison, Thomas Alva, 1847–1931, American inventor, b. Milan, Ohio. A genius in the practical application of scientific principles, Edison was one of the greatest and most productive inventors of his...

dubnium

(Encyclopedia)dubnium do͞obˈnēəm [key], artificially produced radioactive chemical element; symbol Db; at. no. 105; mass number of most stable isotope 268; m.p., b.p., and sp. gr. unknown; valence +5. Situated ...