Iodine

Iodine is a chemical element. Its atomic number (which is the number of protons in it) is 53, and its atomic mass (the number of protons plus neutrons) is 127. It is part of the Group 7 (halogens) on the periodic table of elements and its electronic configuration is 2,8,8,18,17.^[1] It is a nonmetal.

1. ↑ "Iodine Element Facts". Chemicool. Retrieved 2011-03-16.