protons - Definitions from Dictionary.com

2 results for: protons

American Heritage Dictionary - Cite This Source - Share This

pro·ton Audio Help (prō'tŏn') Pronunciation Key
n. Abbr. p
A stable, positively charged subatomic particle in the baryon family having a mass 1,836 times that of the electron. See Table at subatomic particle.

[From Greek prōton, neuter of prōtos, first; see per¹ in Indo-European roots.]

pro·ton'ic adj.

(Download Now or Buy the Book)

The American Heritage® Dictionary of the English Language, Fourth Edition
Copyright © 2006 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.

Encyclopædia Britannica, Inc.
protons

To learn more about protons visit Britannica.com

The American Heritage Science Dictionary - Cite This Source - Share This

proton Audio Help (prō'tŏn') Pronunciation Key
A stable subatomic particle in the baryon family having a mass of 1.672 × 10^-24 grams (1,836 times that of the electron) and a positive electric charge of approximately 1.602 × 10^-19 coulombs. Protons make up part of the nucleus of all atoms except hydrogen, whose nucleus consists of a single proton. In neutral atoms, the number of protons is the same as the number of electrons. In positively charged atoms, the number of protons is greater than the number of electrons, and in negatively charged atoms electrons outnumber protons. Protons are believed to be composed of two up quarks and one down quark. See Table at subatomic particle.

The American Heritage® Science Dictionary
Copyright © 2002 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.

Browse Nearby Entries: