The alpha decay of lead-210 can be represented by the following balanced nuclear equation:
²¹⁰Pb → ²⁰⁶Bi + ⁴He
In this decay process, lead-210 (²¹⁰Pb) loses an alpha particle, which is made up of 2 protons and 2 neutrons (⁴He). As a result of this decay, lead transforms into bismuth (²⁰⁶Bi). Since an alpha particle is emitted, the atomic number decreases by 2 and the mass number decreases by 4, balancing the reaction.