Hydrogen

Position of hydrogen in the periodic table.

Hydrogen is a chemical element with the symbol H and atomic number 1. Hydrogen is the lightest chemical element in the periodic table. At standard conditions hydrogen is a gas of diatomic molecules having the formula H₂. It is colorless, odorless, tasteless, non-toxic, and highly combustible. Hydrogen is the most abundant chemical substance in the universe, constituting roughly 75% of all normal matter. Most of the hydrogen on Earth exists in molecular forms such as water and organic compounds.

Industrial production is mainly from steam reforming of natural gas, oil reforming, or coal gasification. A small percentage is also produced using more energy-intensive methods such as the electrolysis of water. Most hydrogen is used near the site of its production, the two largest uses being fossil fuel processing (e.g., hydrocracking) and ammonia production, mostly for the fertilizer market. It can be burned to produce heat or combined with oxygen in fuel cells to generate electricity directly, with water being the only emissions at the point of usage. Hydrogen atoms (but not gaseous molecules) are problematic in metallurgy because they can embrittle many metals.

Dependencies

• Hydrogen
• Oxygen
  • Water
• Boron
  • Boric acid
• Nitrogen
  • Ammonia
  • Nitric acid
• Carbon
  • Methane
• Sulfur
  • Sulfuric acid

See also

• Chlorine
• Helium
• Iodine
• Phosphorus
• Chemical elements

References

This article uses material from the Wikipedia article Hydrogen, which is released under the Creative Commons Attribution-ShareAlike 3.0 Unported License (view authors).