Oddly enough, the exact number of naturally-occurring elements is uncertain. Uranium (atomic number=92) is the element with the highest atomic number found in significant quantities on earth or elsewhere. The elements astatine (atomic number=85) and francium (atomic number=87), along with all the other known elements (up to atomic number 109) were discovered when first made artificially; if they occur naturally, then they exist only in exceedingly small amounts.

For more information, see:

P.A. Cox. 1989. The Elements: Their origin, abundance, and distribution Oxford Univ. Press, Oxford. ISBN 0-19-855275-0

and WebElements

This page was last modified by Phillip Barak, Univ. of Wisconsin, on 11 Jan 97. All rights reserved.