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niobium

(Encyclopedia)niobium nīōˈbēəm [key], metallic chemical element; symbol Nb; at. no. 41; at. wt. 92.90638; m.p. about 2,468℃; b.p. 4,742℃; sp. gr. 8.57 at 20℃; valence +2, +3, +4, or +5. Niobium is a rare...

neon

(Encyclopedia)neon nēˈŏn [key] [Gr.,=new], gaseous chemical element; symbol Ne; at. no. 10; at. wt. 20.1797; m.p. −248.67℃; b.p. −246.048℃; density 0.8999 grams per liter at STP; valence 0. Neon is a col...

neptunium

(Encyclopedia)neptunium nĕpto͞oˈnēəm [key], radioactive chemical element; symbol Np; at. no. 93; mass number of most stable isotope 237; m.p. about 640℃; b.p. 3,902℃ (estimated); sp. gr. 20.25 at 20℃; va...

cadmium

(Encyclopedia)cadmium kădˈmēəm [key] [from cadmia, Lat. for calamine, with which cadmium is found associated], metallic chemical element; symbol Cd; at. no. 48; at. wt. 112.411; m.p. 321℃; b.p. 765℃; sp. gr...

biochemistry

(Encyclopedia)biochemistry, science concerned chiefly with the chemistry of biological processes; it attempts to utilize the tools and concepts of chemistry, particularly organic and physical chemistry, for elucida...

Kursk

(Encyclopedia)Kursk ko͝orsk [key], city (1989 pop. 424,000), capital of Kursk region, W European Russia, at the confluence of the Tuskor and Seim rivers. An important rail junction, it has machine, chemical, and s...

Maribor

(Encyclopedia)Maribor mäˈrĭbôr [key], Ger. Marburg, city (1991 pop. 103,961), in Slovenia, on the Drava River. It is a heavy industrial center with chemical, engineering, and electrical industries. Known as ear...

Mulliken, Robert Sanderson

(Encyclopedia)Mulliken, Robert Sanderson, 1896–1986, American chemist, b. Newburyport, Mass., Ph.D. Univ. of Chicago, 1921. Mulliken taught at New York Univ. from 1926 to 1928 and then at the Univ. of Chicago fro...

Graham, Thomas

(Encyclopedia)Graham, Thomas, 1805–69, Scottish chemist, best known for research in diffusion in both gases and liquids that led to his formulation of Graham's law. His discovery that certain substances (e.g., gl...

ammonium chloride

(Encyclopedia)ammonium chloride əmōˈnēəm klôrˈīd [key], chemical compound, NH4Cl, a white or colorless, odorless, water-soluble, cubic crystalline salt with a biting taste, commonly known as sal ammoniac. I...