from The American Heritage® Dictionary of the English Language, 4th Edition
- n. An electron in an outer shell of an atom that can participate in forming chemical bonds with other atoms.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. any of the electrons in the outermost shell of an atom; capable of forming bonds with other atoms
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. an electron in the outer shell of an atom which can combine with other atoms to form molecules
Sorry, no etymologies found.