Number of alpha decays is 4.
₉₀Th²³² → ₂He⁴ + ₈₈Ra²²⁸ ∴ α = ₂He⁴
Since, atomic number change by 2 in each alpha decay.
Total charge = 90 -82 = 8
Number of alpha decay = 8/2 = 4.
Alpha decay or α-decay is a type of radioactive decay wherein an atomic nucleus emits an alpha particle (helium nucleus) and thereby transforms or 'decays' into a extraordinary atomic nucleus, with a mass wide variety this is decreased through 4 and an atomic wide variety this is decreased through two.
Alpha decay - A common mode of radioactive decay wherein a nucleus emits an alpha particle (a helium-four nucleus). Beta decay - A commonplace mode of radioactive decay in which a nucleus emits beta particles. The daughter nucleus will have a better atomic number than the original nucleus.
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