Acetylene 1.1614 Air 1.2923 Ammonia 0.7617 Carbon dioxide 1.9641 Carbon monoxide 1.2499 Chlorine 3.1650 Hydrocyanic acid 1.2036 Hydrochloric acid 1.6275 Hydrogen 0.08984 Hydrosulphuric acid 1.5211 Methane 0.7157 Nitric oxide 1.3410 Nitrogen 1.2501 Nitrous oxide 1.9677 Oxygen 1.4285 Sulphur dioxide 2.8596 Densities and Melting Points of Some Common Elements DENSITY MELTING POINT Aluminium 2.68 640 Antimony 6.70 432 Arsenic 5.73 -- Barium 3.75 -- Bismuth 9.80 270 Boron 2.45 -- Cadmium 8.67 320 Caesium 1.88 26.5 Calcium 1.54 -- Carbon, Diamond 3.50 -- " Graphite 2.15 -- " Charcoal 1.80 -- Chromium 7.30 3000 Cobalt 8.55 1800 Copper 8.89 1084 Gold 19.30 1064 Iridium 22.42 1950 Iron 7.93 1800 Lead 11.38 327 Lithium 0.59 186 Magnesium 1.75 750 Manganese 8.01 1900 Mercury 13.596 -39.5 Nickel 8.9 1600 Osmium 22.47 -- Palladium 11.80 1500 Phosphorus 1.80 45 Platinum 21.50 1779 Potassium 0.87 62.5 Rhodium 12.10 -- Rubidium 1.52 38.5 Ruthenium 12.26 -- Silicon 2.35 -- Silver 10.5 960 Sodium 0.97 97.6 Strontium 2.50 -- Sulphur 2.00 114.8 Tin 7.35 235 Titanium 3.50 -- Zinc 7.00 420