Question: Is there metal more radioactive than uranium

Robert Woolfson answered on 16 Mar 2015:

Actually, yes. There’s an element called Polonium which is hugely more toxic than uranium, or even cyanide. 1 thousands of a gram will probably kill you and it has no uses outside of very special science experiments. A russian guy was killed with it in London a few years ago.

There’s also a particular type of caesium which can be found in nuclear reactors and weapons. If it escapes, it dissolves in water and gets into the body really easily which makes it really bad.

However, both of these are really rare and hard to get hold of.