Question

When bismuth-212 undergoes alpha decay, it becomes which of the following? asatine-208 + an alpha particle lead-210 + an alpha particle polonium-210 + and alpha particle thallium-208 + and alpha particle

Answer 1

An alpha particle consists of 2 protons and 2 neutrons. When an alpha particle is emitted, the mass number decreases by 4 and atomic number by 2.

Atomic number of Bismuth-212 is 83. The resulting nucleus after the emission of alpha particle has mass number 208 and atomic number 81. Atomic number 81 corresponds to Thallium-208. Hence the correct choice is "Thallium-208 + and alpha particle".