Hey there

Most rare naturally occurring element ( not artificial) is astatine. It's decay time is very short. It's most stable isotope is Astatine-210 having a half life of 8.1 hours.

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Hii aspirants

Let me clear your doubt.

Astatine  is the rarest of the natural elements present in the Earth's crust.its atomic number is 85.It is a naturally occurring semi-metal that is formed  from the decay of uranium and thorium

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