In its most common form, hydrogen is a gas. It weighs only about one-fourteenth as much as an equal volume of air. Because it is the lightest gas, it was once used for filling balloons and airships. A volume of 13,080 cubic yards (10,000 cubic meters) of hydrogen at 32° F. (0° C) and 1 atmosphere pressure can lift about 13.5 short tons (12.2 metric tons). However, it is inflammable. So airships are now filled with helium, the next lightest element.
An unusual property of hydrogen is its effect on sound. Because it is lighter than air, sound waves travel more quickly through hydrogen. The pitch of the sound is thus higher.
As a gas, hydrogen is usually transported in steel cylinders at 120 to 150 atmospheres pressure. It is only slightly soluble in water. Although it cannot support life, it is also not poisonous.
Hydrogen can be condensed to a liquid at a temperature of —464° F. ( — 258° C). In this form it is used as a rocket fuel. It is transported in
thermally insulated containers. Compounds and uses of hydrogen
Hydrogen forms many compounds. It is a component of water, two atoms of hydrogen combining with one atom of oxygen to make a water molecule. It is a part of the common acids and many bases. Hydrogen also forms organic compounds by combining with other chemical elements in plant and animal tissues. It reacts with metals and many other minerals.
About half of the hydrogen produced industrially is converted into ammonia. The ammonia is oxidized (combined with oxygen) to nitrogen oxide, which is then converted to nitric acid for making fertilizers and explosives.
Other important uses of hydrogen include the purification of oil refinery products, for example, the "upgrading" of heavy fuel oil to gas-
fusion of deuterium and tritium nuclei
Large amount of energy released
Free neutron resulting from fusion reaction
Helium nucleus formed
A hydrogen bombexplosion /right) produces an enormous amount of energy virtually instantaneously. It works in two main stages. First, an atomic (fission) bomb explodes to produce the extremely high pressure and temperature needed for the second stage, the fusion reaction. In a fission reaction, atoms are split to produce energy. In a fusion reaction (right, top), nuclei of deuterium and tritium fuse. This produces a helium nucleus, a free neutron, and a large amount of energy. Scientists are trying to develop fusion reactors in which the energy of fusion can be controlled and used to generate electricity.
Major groups of elements: Hydrogen 25
oline. Hydrogen is also used in the production of methanol, which is a basic ingredient in many fuels, rubbing compounds, and solvents.
Hydrogen and carbon (coal) together form various hydrocarbons. These are compounds that include petroleum and natural gas, which provide energy for cooking, heating, and running automobiles. A process known as hydro-genation is the adding of hydrogen to liquid fats in order to form solid fats. Hydrogenation of vegetable oils produces margarine. Hydrogenation of animal fats and oils produces semisolid shortenings used in cooking.
Hydrogen is also involved in the production of liquid fuels from coal. This method of producing energy, however, is uneconomical.
When two hydrogen atoms unite to form a molecule of hydrogen, or when hydrogen unites with oxygen, relatively large amounts of heat are given off. If a method could be found to better control these chemical reactions and store the released energy, hydrogen could become the energy carrier of the future.
Scientists have already developed ways of producing hydrogen economically and in quantity from water. They are currently researching ways of releasing the energy inside hydrogen more efficiently and safely. Currently, hydrogen fuel powers the main engine of the United States space shuttle while in orbit. A power plant in New York City produces electricity by means of hydrogen fuel. Hydrogen-powered automobiles and commercial aircraft are in various stages of development.