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 IGCSE question that was asking students to predict a group 7 element that was solid at room temperature and was NOT iodine.

As I could not find anything out, I consulted my favourite book [see earlier posts, but for information it is ‘Natures Building Blocks by John Emsley ISBN 0-19-850340-7] as I knew this would contain the information I was searching for.

And here we go:

This element has never been seen! It is immensely radioactive and does not occur naturally (it did in the past but it has all decayed by now) – world production is estimated to be less than one millionth of a gram and it is among the ten least abundant elements!¹

So there we have it – there is not much chance that you will be able to order it to show how it reacts with iron or sublimes like astatine and as for watching clips on YouTube (if there are any) – they will probably be fake!

¹ Source: Natures Building Blocks by John Emsely, ISBN 0-19-850340-7, pages 47 & 48, first issue, Oxford University Press.