an abundant nonmetallic tetravalent element occurring in three allotropic forms: amorphous carbon and graphite and diamond; occurs in all organic compounds
a silver-white metallic element of the platinum group that resembles platinum; occurs in some copper and nickel ores; does not tarnish at ordinary temperatures and is used (alloyed with gold) in jewelry
the state of matter distinguished from the solid and liquid states by: relatively low density and viscosity; relatively great expansion and contraction with changes in pressure and temperature; the ability to diffuse readily; and the spontaneous tendency to become distributed uniformly throughout any container
a fluid in the gaseous state having neither independent shape nor volume and being able to expand indefinitely
attack with gas; subject to gas fumes; "The despot gassed the rebellious tribes"
tending to or capable of propelling; "propellant fuel for submarines"; "the faster a jet plane goes the greater its propulsive efficiency"; "universities...the seats of propulsive thought"
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
a score in American football; a player is tackled behind his own goal line
a safe place; "He ran to safety"
the state of being certain that adverse effects will not be caused by some agent under defined conditions; "insure the safety of the children"; "the reciprocal of safety is risk"