(n) a common nonmetallic element belonging to the halogens; best known as a heavy yellow irritating toxic gas; used to purify water and as a bleaching agent and disinfectant; occurs naturally only as a salt (as in sea water), Syn. Cl, atomic number 17
(n) a nonmetallic univalent element that is normally a colorless and odorless highly flammable diatomic gas; the simplest and lightest and most abundant element in the universe, Syn. atomic number 1, H
(n) a light silver-white ductile bivalent metallic element; in pure form it burns with brilliant white flame; occurs naturally only in combination (as in magnesite and dolomite and carnallite and spinel and olivine), Syn. Mg, atomic number 12
(n) a radioactive transuranic element synthesized by bombarding einsteinium with alpha particles (Md is the current symbol for mendelevium but Mv was formerly the symbol), Syn. atomic number 101, Mv, Md
(n) a colorless odorless gaseous element that give a red glow in a vacuum tube; one of the six inert gasses; occurs in the air in small amounts, Syn. Ne, atomic number 10
(n) a multivalent nonmetallic element of the nitrogen family that occurs commonly in inorganic phosphate rocks and as organic phosphates in all living cells; is highly reactive and occurs in several allotropic forms, Syn. atomic number 15, P
(n) a light soft silver-white metallic element of the alkali metal group; oxidizes rapidly in air and reacts violently with water; is abundant in nature in combined forms occurring in sea water and in carnallite and kainite and sylvite, Syn. atomic number 19, K
(n) a tetravalent nonmetallic element; next to oxygen it is the most abundant element in the earth's crust; occurs in clay and feldspar and granite and quartz and sand; used as a semiconductor in transistors, Syn. Si, atomic number 14
(n) a silvery soft waxy metallic element of the alkali metal group; occurs abundantly in natural compounds (especially in salt water); burns with a yellow flame and reacts violently in water; occurs in sea water and in the mineral halite (rock salt), Syn. Na, atomic number 11
(n) an abundant tasteless odorless multivalent nonmetallic element; best known in yellow crystals; occurs in many sulphide and sulphate minerals and even in native form (especially in volcanic regions), Syn. atomic number 16, S, sulphur