fourth quantum number
fourth quantum number
n.
The quantum number that specifies the direction of the spin of an electron in an atom and has a value of + 1/2 or - 1/2 . Also called spin quantum number.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.