Radon-222 decays by alpha emission to form a new nuclide. Identify the new nuclide.

Question

Quizplus · Accepted Answer

When radon-222 undergoes alpha decay, it loses an alpha particle (two protons and two neutrons). This means the atomic number decreases by two, and the mass number decreases by four. Therefore, the new nuclide must have an atomic number that is two less than 86 (the atomic number of radon) and a mass number that is four less than 222. The only option that fits this criteria is polonium-218 (atomic number 84, mass number 218).

Radon-222 Decays by Alpha Emission to Form a New Nuclide