What is Hydrogen?

     Hydrogen is a naturally occurring gas that is amazingly light. Hydrogen is, in fact, the lightest gas ever found. Hydrogen has no color, no smell and no taste. The hydrogen atom is so simple and small, it is hard to believe that hydrogen is the most important and abundant substance in the universe. Hydrogen atoms are the building blocks of other atoms.

The Hydrogen Atom

      Hydrogen was the first element ever discovered and put on the periodic table (the periodic symbol H).  The hydrogen atom has only one electron circling the nucleus. Hydrogen is the simplest element as it has only one nucleus, one shell and one electron (See Fig. 3).

Where is Hydrogen?

      Ninety per cent of all of the universe’s atoms are hydrogen. The Sun, all of the stars and large planets are made of hydrogen combined with other gases (mostly Helium). Hydrogen is the fuel that makes stars burn. The earth is not made mostly of hydrogen because the earth is small (less gravity) and hydrogen is light, so the hydrogen that was here, has mostly escaped the gravitational pull of Earth.

     On Earth, hydrogen can be found in many places. Hydrogen combines with oxygen to form water, which is essential for life on earth. Water makes up three quarters of the earth’s surface (See Fig. 4). Three quarters of our bodies are made of water. Fossil fuels are made of hydrocarbons, a combination of hydrogen and carbon.  Other hydrogen compounds are proteins, cellulose, sugars and amino acids.

Hydrogen Reactions

     Hydrogen is one of the most reactive substances in the world. The small size and mass of hydrogen makes hydrogen easily mixable with other atoms. A very little amount of hydrogen will cause a reaction. Hydrogen has a gap in its shell because it has only one electron. Hydrogen becomes a charged ion, making it unstable. Therefore, hydrogen combines with other atoms easily.

     Flammability is also a trait of hydrogen. (See Fig. 5)  Water is produced when hydrogen is burned in oxygen. Hydrogen and oxygen molecules are very attracted to each other and combine to make water. The animation below illustrates the small hydrogen molecules (red) combining with the larger oxygen molecule (blue) to make water (H20).

Hydrogen Production

     Hydrogen cars will require a large amount of hydrogen to be produced, for the hydrogen cars to be efficient. Pure hydrogen gas is very hard to come by, as it exists only in small underground pockets. This means that hydrogen may need to be produced artificially, from either fossil fuels or water. The splitting of hydrogen compounds uses a lot of energy. Currently most hydrogen is made by passing steam through natural gas, creating a compound of carbon monoxide and hydrogen. The compound is purified by changing the carbon monoxide to carbon dioxide and then the carbon dioxide is dissolved in water. Hydrogen is left behind after this process.

     Scientists are looking for new methods of producing hydrogen that are more environmentally friendly. One prospect is using heat-loving bacteria found in hydrothermal volcanic vents beneath the ocean (See Fig. 6). The bacteria may allow us to make hydrogen from glucose in wood and waste paper.