The Elements - Periodic Table

Hydrogen

For rocket fuel

Atomic Number: 1

Atomic Symbol: H

Atomic Weight: 1.0079

Electron Configuration: 1s^1

History

(Gr. hydro, water, and genes, forming) Hydrogen was prepared many years before it was
recognized as a distinct substance by Cavendish in 1776.

Named by Lavoisier, hydrogen is the most abundant of all elements in the universe. The heavier
elements were originally made from Hydrogen or from other elements that were originally
made from Hydrogen.

Sources

Hydrogen is estimated to make up more than 90% of all the atoms or three quarters of the mass
of the universe. This element is found in the stars, and plays an important part in powering the
universe through both the proton-proton reaction and carbon-nitrogen cycle -- stellar hydrogen
fusion processes that release massive amounts of energy by combining Hydrogen to form
Helium.

Production of hydrogen in the U.S. alone now amounts to about 3 billion cubic feet per year.
Hydrogen is prepared by

steam on heated carbon,

decomposition of certain hydrocarbons with heat,

action of sodium or potassium hydroxide on aluminum

electrolysis of water, or

displacement from acids by certain metals.

Liquid hydrogen is important in cryogenics and in the study of superconductivity, as its melting
point is only 20 degrees above absolute zero.

Tritium is readily produced in nuclear reactors and is used in the production of the hydrogen
bomb.

Hydrogen is the primary component of Jupiter and the other gas giant planets. At some depth in the

Hydrogen