Astatine (At)

We have probably all mentioned Astatine in our teaching at some point - probably in relation to the trends and patternss of group 7 elements. You know the usual patter - melting points increase as you go down the group, the colour gets darker and so on. One of my students asked me what colour it actually was - we looked but could not find any photos of it. The students curiosity came from not an iB question but an ...

Astatine (At)

  Astatine comes after Iodine in group 7 of the periodic table. Mendeleev famously left a space for it when he put his periodic table together. The Guinness Book of World Records has called Astatine the rarest element on Earth. At any one time there is less than 25g of it present. It was first produced in 1940 at the University of California by Emilio Serge by bombarding Bismuth with Helium ions (He2+). The stalest isotope of Astatine   has a half life of ...