Period 5 element blood cells in the body. Tin is a chemical element with the symbol Sn (for ) and atomic number 50. It is a main group metal in group 14 of the periodic table. Tin shows chemical similarity to both neighboring group 14 elements, germanium and lead and has two possible 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. Tin is obtained chiefly from the mineral cassiterite, where it occurs as tin dioxide, SnO. This silvery, malleable
SN 1885A brightness, which is atypical for Type Ia supernovae. Some astronomers observed the spectrum of the star visually (no photographic spectral observations were made in that time). These observations were made at the limit of visibility, but they were considered to be in good agreement with each other and with modern data on typical supernovae of Type Ia; so SN 1885A had been assigned to this type. Recent studies led by Dovi Poznanski and by Hagai Perets suggest that SN 1885A belongs in a new subclass of Type I supernovae along with SN 2002bj and SN 1939B. The location of the