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 1054 and SN 1181) reveals a proximity in the dates of discovery of a guest star in China and Japan, although clearly based on different sources. Fujiwara no Teika's interest in the guest star seems to have come accidentally whilst observing a comet in December 1230, which prompted him to search for evidence of past guest stars, among those SN 1054 (as well as SN 1006 and SN 1181, the two other historic supernovas from the early second millennium). The entry relating to SN 1054 can be translated as: The source used by Fujiwara no Teika is the records of Yasutoshi