Question

polonium has a mass number of 212 and an atomic number of 84. in a balanced nuclear reaction, polonium releases an alpha particle to produce lead. which option is the atomic number of lead? (1 point)
210
82
80
208

Explanation:

Step1: Recall alpha - particle composition

An alpha - particle is $_{2}^{4}\text{He}$, which has a mass number of 4 and an atomic number of 2.

Step2: Use conservation of atomic number in nuclear reaction

Polonium has an atomic number of 84 ($Z = 84$). When it emits an alpha - particle, the atomic number of the resulting lead is $Z_{Pb}=84 - 2=82$.

Answer:

82