What is the daughter nucleus (nuclide) produced when At217 undergoes alpha decay? Replace the question marks with the proper integers or symbols.

Question

What is the daughter nucleus (nuclide) produced when  undergoes alpha decay? Replace the question marks with the proper integers or symbols.

Answer 1

An alpha decay is when a nucleus loses two protons and two neutrons. Therefore the Atomic Number (the number of protons) will decrease by two, and the Mass Number (the number of protons and neutrons) will decrease by four.

You will need to lookup Astatine on a periodic table to find its Atomic Number. Its Mass Number is given. Don't forget to change At to the symbol of the new nucleus.