Tin Tin Tin is a chemical element with the symbol Sn (from ) and atomic number 50. It is a post-transition metal in group 14 of the periodic table of elements. It is obtained chiefly from the mineral cassiterite, which contains stannic oxide, SnO. Tin shows a chemical similarity to both of its neighbors in group 14, germanium and lead, and has two main oxidation states, +2 and the slightly more stable +4. Tin is the 49th most abundant element and has, with 10 stable isotopes, the largest number of stable isotopes in the periodic table, thanks to its magic number
SN 2014J ± 0.3 megaparsecs), SN 2014J was one of the closest supernovae seen for decades. It was the closest type Ia supernova since SN 1972E, and the closest supernova of any type since 2004. Some sources initially stated that SN 2014J was the closest supernova of any type since SN 1987A, but this claim is erroneous. The last supernova that was unambiguously closer to Earth than SN 2014J was SN 2004dj, a type II-P supernova in the galaxy NGC 2403, 8 million light-years from Earth. SN 1993J was a type IIb supernova at almost the same distance as SN 2014J, because