How many alpha and beta particles are emitted when Uranium ${\mathrm{U}}_{92}^{238}$ decays to lead ${\mathrm{Pb}}_{82}^{206}$ ?

On emission of one alpha particle, the mass number decreases by 4 and the atomic number decreases by 2 but when a β-particle is emitted, the mass number remain same and the atomic number increases by 1.

Decrease in Mass Number = 238 – 206 = 32

Decrease in Atomic Number = 92 – 82 = 10