Plutonium is a radioactive, silvery metal that yellows when exposed to oxygen. It is represented on the Periodic Table of Elements by the symbol "Pu". Plutonium is one of the transuranium elements in the actinide series of the Periodic Table. Its atomic number is 94. Plutonium has an atomic mass of 244 and a density of 298K. Pu melts at 914 degrees Kelvin. Its valence number is 2, and it has a relative electro negativity of 1.28. Plutonium has many naturally occuring isotopes, but occurs very rarely in natural settings: 228, 229, 230, 232, 233, 234, 235, 236, 237, 237a, 238, 238a, 239, 24…