Tin mg/m over an 8-hour workday. At levels of 100 mg/m, tin is immediately dangerous to life and health. 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
SN 2005bc of the supernova at around −18.6 at maximum, rather faint for a Type Ia event. As the supernova was of Type Ia, its progenitor star was a White Dwarf star which exceeded the Chandrasekhar limit. Below is an image of SN 2005bc and NGC 5698 taken just over a week after peak brightness. SN 2005bc SN 2005bc was a Type Ia supernova occurring in the Barred spiral galaxy NGC 5698 in the constellation of Boötes. SN 2005bc was discovered on 2 April 2005 by LOSS and independently by Tim Puckett and L. Cox. The supernova was at magnitude 16.4 at