* Beta Decay: Beta decay is a type of radioactive decay where a neutron in the nucleus of an atom decays into a proton, an electron (beta particle), and an antineutrino.
* Bismuth-210: Bismuth-210 has 83 protons and 127 neutrons.
* Polonium-210: After beta decay, the number of protons increases by one (83 to 84), and the number of neutrons decreases by one (127 to 126). This results in an atom of polonium-210, which has 84 protons and 126 neutrons.
Here's the equation for the beta decay of bismuth-210:
```
²¹⁰Bi → ²¹⁰Po + ⁰⁻¹e + ν̄ₑ
```
Where:
* ²¹⁰Bi represents bismuth-210
* ²¹⁰Po represents polonium-210
* ⁰⁻¹e represents the electron (beta particle)
* ν̄ₑ represents the antineutrino
