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)
Responses

80
80

210
210

82
82

208

Answers

GPT-4o mini
In a balanced nuclear reaction involving polonium-212 (atomic number 84) releasing an alpha particle (which is a helium nucleus with an atomic number of 2), the reaction can be represented as follows:

\[
^{212}_{84}\text{Po} \rightarrow ^{4}_{2}\text{He} + ^{A}_{Z}\text{Pb}
\]

When polonium emits an alpha particle, the atomic number decreases by 2 (because the alpha particle has an atomic number of 2), and the mass number decreases by 4 (since the alpha particle has a mass number of 4).

So, the atomic number of lead can be calculated as follows:

- Original atomic number of polonium: 84
- Atomic number after emission: \(84 - 2 = 82\)

The mass number will also decrease by 4:

- Original mass number of polonium: 212
- Mass number after emission: \(212 - 4 = 208\)

Therefore, the lead produced will have:

- Atomic number: 82
- Mass number: 208

Thus, the correct response for the atomic number of lead is **82**.