Go to MSN Homeencarta®
Dictionary
Find
in
Dictionary
Thesaurus
Translations
ABCDEFGHIJKLMNOPQRSTUVWXYZ
Click to move up the list of words
actinopterygian
actinouranium
action
action figure
action game
action group
action item
action man
action movie
action officer
action-packed
action painting
action potential
action replay
action spectrum
action stations
action to quiet title
Click to move down the list of words
Also available:

World English Dictionary
Dictionnaire Français

actinium
ac·tin·i·um [ ak tínnee əm ]


noun 
Definition:
 
radioactive element: a radioactive silvery white metallic element. Source: pitchblende. Use: source of alpha rays.
Symbol  Ac
[Early 20th century. < Greek aktin- "ray"]
Encarta® World English Dictionary [North American Edition] © & (P)2009 Microsoft Corporation. All rights reserved. Developed for Microsoft by Bloomsbury Publishing Plc.
Advertisement
© 2009 Microsoft