Hydrogen is colourless, odourless, tasteless, flammable, and non
toxic gas at atmospheric temperatures and pressures. The gas
burns in air with a pale blue, almost invisible flame.
It is the lightest of all gases appropriate of 1/5 as heavy as air,
It is manufactured industrially by either electrolysis, of water, steam, reformation, of hydrocarbons or partial oxidation of coal or hydrocarbons.