a very poisonous metallic element that has three allotropic forms; arsenic and arsenic compounds are used as herbicides and insecticides and various alloys; found in arsenopyrite and orpiment and realgar
a white powdered poisonous trioxide of arsenic; used in manufacturing glass and as a pesticide (rat poison) and weed killer
a nonmetallic bivalent element that is normally a colorless odorless tasteless nonflammable diatomic gas; constitutes 21 percent of the atmosphere by volume; the most abundant element in the earth's crust
a bluish translucent magnetic liquid obtained by compressing gaseous oxygen and then cooling it below its boiling point; used as an oxidizer in rocket propellants
a colorless nonflammable liquid used as a solvent for fats and oils; because of its toxicity its use as a cleaning fluid or fire extinguisher has declined
a common nonmetallic element that is normally a colorless odorless tasteless inert diatomic gas; constitutes 78 percent of the atmosphere by volume; a constituent of all living tissues
a heavy odorless colorless gas formed during respiration and by the decomposition of organic substances; absorbed from the air by plants in photosynthesis
air passage provided by a retractable device containing intake and exhaust pipes; permits a submarine to stay submerged for extended periods of time
breathing device consisting of a bent tube fitting into a swimmer's mouth and extending above the surface; allows swimmer to breathe while face down in the water