Columbia Encyclopedia

Search results

162 results found

chloride

(Encyclopedia)chloride klōrˈīd, klôrˈ– [key], chemical compound containing chlorine. Most chlorides are salts that are formed either by direct union of chlorine with a metal or by reaction of hydrochloric ac...

moscovium

(Encyclopedia)moscovium mŏskōˈvēəm [key], artificially produced radioactive chemical element; symbol Mc; at. no. 115; mass number of most stable isotope 288; m.p., b.p., sp. gr., and valence unknown. Situated ...

centripetal force and centrifugal force

(Encyclopedia)CE5 Centripetal and centrifugal forces: When a ball is swung in a circle at the end of a string, centripetal and centrifugal forces act as shown above. centripetal force and centrifugal force, act...

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 ...

salt, chemical compound

(Encyclopedia)salt, chemical compound (other than water) formed by a chemical reaction between an acid and a base (see acids and bases). Salts are also prepared by methods other than neutralization. A metal can c...

alcohol

(Encyclopedia)CE5 Alcohols alcohol, any of a class of organic compounds with the general formula R–OH, where R represents an alkyl group made up of carbon and hydrogen in various proportions and –OH represe...

meson

(Encyclopedia)meson mēˈzŏn [key] [Gr.,=middle (i.e., middleweight)], class of elementary particles whose masses are generally between those of the lepton class of lighter particles and those of the baryon class ...

condensate

(Encyclopedia)condensate, matter in the form of a gas of atoms, molecules, or elementary particles that have been so chilled that their motion is virtually halted and as a consequence they lose their separate ident...

atomic clock

(Encyclopedia)atomic clock, electric or electronic timekeeping device that is controlled by atomic or molecular oscillations. A timekeeping device must contain or be connected to some apparatus that oscillates at a...

oganesson

(Encyclopedia)oganesson ōˈgənĕsˌən [key], artificially produced radioactive chemical element; symbol Og; at. no. 118; mass number of most stable isotope 294; m.p., b.p., sp. gr., and valence unknown. Situated...

Browse by Subject