ar

Science Dictionary
Ar  
The symbol for argon.
American Heritage
Science Dictionary
argon   (är'gŏn')  Pronunciation Key 
Symbol Ar
A colorless, odorless element in the noble gas group. Argon makes up about one percent of the atmosphere. It is used in electric light bulbs, fluorescent tubes, and radio vacuum tubes. Atomic number 18; atomic weight 39.948; melting point -189.2°C; boiling point -185.7°C. See Periodic Table.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
Copyright © 2014 Dictionary.com, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature