Columbia Encyclopedia

Search results

500 results found

lead acetate

(Encyclopedia)lead acetate, chemical compound, a white crystalline substance with a sweetish taste. Like other lead compounds, it is very poisonous. Lead acetate is soluble in water and glycerin. With water it form...

tear gas

(Encyclopedia)tear gas, gas that causes temporary blindness through the excessive flow of tears resulting from irritation of the eyes. The gas is used in chemical warfare and as a means for dispersing mobs. Compoun...

bromine

(Encyclopedia)bromine brōˈmēn, –mĭn [key] [Gr.,=stench], volatile, liquid chemical element; symbol Br; at. no. 35; at. wt. 79.904; m.p. –7.2℃; b.p. 58.78℃; sp. gr. of liquid 3.12 at 20℃; density of va...

catabolism

(Encyclopedia)catabolism kətăbˈəlĭzˌəm [key], subdivision of metabolism involving all degradative chemical reactions in the living cell. Large polymeric molecules such as polysaccharides, nucleic acids, and ...

formula, in chemistry

(Encyclopedia)formula, in chemistry, an expression showing the chemical composition of a compound. Formulas of compounds are used in writing the equations (see chemical equations) that represent chemical reactions....

Magnus, Heinrich Gustav

(Encyclopedia)Magnus, Heinrich Gustav hīnˈrĭkh go͝osˈtäf mägˈno͝os [key], 1802–70, German chemist, physicist, and educator. In 1831 he became lecturer and in 1834 professor of physics and technology at t...

sulfate

(Encyclopedia)sulfate, chemical compound containing the sulfate (SO4) radical. Sulfates are salts or esters of sulfuric acid, H2SO4, formed by replacing one or both of the hydrogens with a metal (e.g., sodium) or a...

ammonium sulfate

(Encyclopedia)ammonium sulfate, chemical compound, (NH4)2SO4, a colorless-to-gray, rhombohedral crystalline substance that occurs in nature as the mineral mascagnite. It is soluble in water and insoluble in alcohol...

potassium carbonate

(Encyclopedia)potassium carbonate, chemical compound, K2CO3, white, crystalline, deliquescent substance that forms a strongly alkaline water solution. It is available commercially as a white, granular powder common...

tabun

(Encyclopedia)tabun täˈbən [key], liquid chemical compound used as a nerve gas. It boils at 240℃ with some decomposition. The liquid is colorless to brownish; its vapors have a fruity odor similar to that of b...