Definition: 'X' is used to denote a halogen in the structural formula of a molecule (usually organic).
X Group Definition
By Anne Marie Helmenstine, Ph.D., About.com
Suggested Reading
Explore Chemistry
Must Reads
More from About.com
Work Hard, Travel Easy
The best tips for business travelers.Dog Care
Get tips on training and caring for dogs of all ages.48 Hours in Vegas
Plan a hot weekend in Sin City.Hotel Advice
The must-stay hotels worldwide.
©2008 About.com, a part of The New York Times Company.
All rights reserved.