What is Polonium-210?
The body of the former Palestinian leader Yasser Arafat will be exhumed on Tuesday to test to see if he was the victim of Polonium-210 poisoning.
Polonium was first discovered by Marie and Pierre Curie in 1898. It is a radioactive element that occurs naturally in the earth's crust.
According to scientists from the University of Chicago Polonium-210 is traditionally used to clear dust from camera lenses or photographic film.
It is poisonous if ingested and it's believe that the Russian dissident Alexander Litvinenko who died in November 2006 was the victim of Polonium-210 poisoning.
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