Ar | Argon |
Atomic number : 18
Relative atomic mass (12C = 12.0000) : 39.948 |
P H Y S I C A L D A T A | |
Group 18 noble gas Density / kg m-3 : 1656 [40 K]; 1380 [liq., b.p.]; 1.748 [273 K] |
Melting point / K : 83.78 Boiling point / K : 87.29 |
D I S C O V E R Y | |
Argon was discovered in 1894 by Lord Rayleigh (London) and Sir William Ramsay (Bristol), England. |
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G E O L O G I C A L D A T A | |
Abundances Sun (relative to H = 1 × 1012) : 1 × 106 Earth's crust / p.p.m. : 1.2 Atmosphere / p.p.m. (volume) : 9300 Residence time / years : 28 000 Oxidation state : 0 |
Seawater / p.p.m. : 0.45 |
B I O L O G I C A L D A T A | |
Level in humans Blood / mg dm-3 : trace Bone / p.p.m. : nil Liver / p.p.m. : nil Muscle / p.p.m. : nil |
Daily dietary intake : n.a., but low Total mass of element in average (70 kg) person : n.a., but small |
A portrait of argon is available on the Visual Elements site. Up to 200 individual items of information on this element are available in The Elements. |