What are the atomic number and the atomic mass of the

Question

element formed when 84
218Po emits a beta particle? What
are they if the polonium emits an alpha particle?

Answer 1

84 218Po: 84 signifies the number of protons; 218 is the atomic mass (#protons + #neutrons)

When a beta particle is emitted, one neutron gets changed to a proton, so if 84 218 Po emits a beta particle, the number of protons will go up by one (atomic number = 85), and the atomic mass will stay the same.

When the polonium emits an alpha particle, it emits 2 protons and 2 neutrons: 82 is the atomic number, and 216 is the atomic mass

Answer 2

Actually, if an Alpha particle is emitted, and the atom loses two protons AND two neutrons, the mass would lower by four; while atomic number counts only protons, mass counts neutrons as well as protons. Therefor, while the number would be 82, the mass would fall to 214.