Definition of argon :
1. A colorless, odorless gas occurring in the air ( of which it constitutes 0. 93 per cent by volume), in volcanic gases, etc.; -- so named on account of its inertness by Rayleigh and Ramsay, who prepared and examined it in 1894- 95. Symbol, A; at. wt., 39. 9. Argon is condensible to a colorless liquid boiling at - 186. 1¡ C. and to a solid melting at - 189. 6¡ C. It has a characteristic spectrum. No compounds of it are known, but there is physical evidence that its molecule is monatomic. Weight of one liter at 0¡ C. and 760 mm., 1. 7828 g.
2. A substance regarded as an element, contained in the atmosphere and remarkable for its chemical inertness.
element (part of speech: noun)
rhenium, zinc, osmium, indium, thallium, astatine, antimony, fluorine, nobelium, cerium, phosphorus, lead, sulfur, yttrium, americium, tungsten, europium, tellurium, erbium, rhodium, neodymium, boron, iridium, magnesium, chromium, manganese, einsteinium, platinum, strontium, element, cadmium, fermium, bismuth, mendelevium, bromine, tantalum, plutonium, gallium, uranium, titanium, ruthenium, lanthanum, cesium, palladium, gadolinium, holmium, cobalt, curium, iron, promethium, aluminum, hafnium, molybdenum, nickel, polonium, terbium, sodium, copper, praseodymium, krypton, mercury, niobium, technetium, berkelium, calcium, selenium, radon, germanium, thorium, potassium, carbon, radium, scandium, lithium, samarium, lutetium, silver, beryllium, californium, dysprosium, gold, zirconium, francium, tin, barium, protactinium, silicon, arsenic, vanadium, ytterbium, actinium, thulium, rubidium, neptunium, iodine
gas (part of speech: noun)
butane, carbon dioxide, neon, ether, ethane, gas, ammonia, hydrogen, laughing gas, oxygen, xenon, methane, chlorine, nitrogen, miasma, fume, tear gas, carbon monoxide, mustard gas, nerve gas, ozone, rarefaction, vapor, natural gas, acetylene, helium, atmosphere