Rock Canyon High School, Littleton, Colorado, U.S.A.
Astatine: The collage represents the element astatine (At). As only a small amount of astatine is actually present in nature, the collage is relatively simple. Astatine’s atomic number is 85 shown in the top left corner of the collage and the symbol (At) is in the top right corner of the collage. The words short and li represent Astatine’s short half-life, as li is half of the word life. The background is the radioactive symbol as astatine is radioactive. The numbers in the three branches of the radioactive symbol equal 1940, the year astatine was discovered at the University of California — represented by the Cal in the bottom left corner. The other picture in the collage is the elemental configuration of astatine just to provide an easy and quick way to identify astatine.
Corinne Carlson, Rock Canyon High School, Littleton, Colorado, U.S.A.
Number of isotopes:
* Haynes, W. M. (2011). CRC Handbook of Chemistry and Physics, 91st edition: http://www.hbcponline.com/ Retrieved April 7, 2011
** Winter, M. (2010). Home of the Periodic Table. Retrieved April 8, 2011, from Web Elements: http://www.webelements.com/