'''Argon''' ('''Ar''') is the most common of the [[noble gas]]ses. It is an inert component which comprises .934% of the [[atmosphere]] of earth.<ref>The New American Desk Encyclopedia, Penguin Group, 1989</ref>
+
'''Argon''' ('''Ar''') is the most common of the [[noble gas]]ses. It is an inert component which comprises 0.934% of the Earth's [[atmosphere]].<ref>The New American Desk Encyclopedia, Penguin Group, 1989</ref>