3.3.2  Hydrogen Data 

• Hydrogen (H2) is the most abundant element in the universe. It is designated “atomic number 1”.
  
  
• At normal atmospheric temperatures and pressures hydrogen is a flammable gas.
  
  
• It is a solid between absolute zero of minus 273.16 degrees C and its melting point of minus 259.34 degrees C, when it becomes a liquid.
  
  
• It remains a liquid in the small band of 6.47 degrees C, until it rises to its boiling point of minus 252.87 degrees C. Note: Water has a boiling point of plus 100 degrees C.
  
  
• It is usually stored as a liquid because when it is converted to gas, hydrogen expands and takes up about 840 times more space.
  
  
• It is the lightest of the gases. About one-fifteenth the weight of air.