What is hydrogen?
Hydrogen is a simple gaseous substance; its molecule consists of only 112 hydrogen atoms.
Hydrogen is several times lighter than air; 1 m³ of hydrogen weighs 89 g.
Hydrogen is the lightest of all gases. Its flash point is 530–590 °C.
The heat of combustion of 1 kg of hydrogen is 118,000 kJ (28,000 kcal).
The boiling point of liquid hydrogen is 252.8 °C.
Natural gas contains almost no pure hydrogen. Artificial gases, such as lighting and coke gases, contain up to 57.6% hydrogen.
