Hydrogen

Hydrogen
Properties
Atomic symbol	H
Atomic number	1
Classification	Gas
Atomic mass	1.001 amu
Other Information

Hydrogen is the most abundant of all the elements, and has the chemical symbol H and an atomic number of 1. Despite this abundance, naturally occurring elemental hydrogen is extremely rare on Earth.

Composition of the atom

Hydrogen atoms normally consist of a single proton and electron, with no neutron. Other isotopes are formed as the atom gains neutrons: deuterium (one neutron) and tritium (two neutrons). Tritium is radioactive, with a half-life of approximately 12 years.

Compounds

Hydrogen can be found in a vast majority of organic compounds, as well as some inorganic compounds. It is an important component of water and most acids.

Fuel for vehicles

Hydrogen is one of two fuels needed for fuel cells (the other being oxygen), which have the potential to be a major form of alternative energy in the future. Fuel cells are very clean energy sources; their only by-products are water and heat. Since no pollutants or greenhouse gases are produced, the use of fuel cells could provide cleaner air and potentially slow down global warming.

Unfortunately, hydrogen is not a viable fuel source at present. Today's average car, for example, would require an unfeasibly large fuel tank to carry enough hydrogen for practical purposes. Hydrogen is also extremely flammable and suitable safeguards are needed to reduce the chances of a fatal explosion in an accident. There is also the issue of obtaining the pure hydrogen needed. Hydrogen can be obtained from distilled water through electrolysis, but this requires the same amount of energy the Hydrogen's use in a fuel cell would yield. Fuel cells would not solve the eventual energy crisis; it would simply move the problem to the power plants providing the energy to obtain the hydrogen through electrolysis.

If hydrogen could be used in cars, it would be important in establishing the hydrogen economy.