Definition: hydrogen: The lightest and most abundant element. A hydrogen atom consists of one proton and one electron. Hydrogen composes about 75 percent of the Sun but only a tiny fraction of the Earth.
hydrogen
From Nick Greene, former About.com Guide
Free Email Courses
Related Articles
- Balmer lines (J. Balmer) - Space and Astronomy Definition - Online Dictiona...
- Kirchhoff's laws (G.R. Kirchhoff) - Space and Astronomy Definition - On...
- Eddington limit (Sir A. Eddington) - Space and Astronomy Definition - Onlin...
- inferior planets - Space and Astronomy Definition - Online Dictionary and G...
- impact crater - Space and Astronomy Definition - Online Dictionary and Glos...
Explore Space / Astronomy
- About.com
- Education
- Space / Astronomy
- Astronomy and Space Basics
- Glossaries
- Astronomy Dictionary
- hydrogen - Space and Astronomy Definition - Online Dictionary and Glossary Definition of hydrogen
©2012 About.com. All rights reserved.
A part of The New York Times Company.