Which of the four radioactive disintegration series is known as the series because the mass numbers — Nuclear Chemistry and Radioactivity Chemistry Question

💡 Solution & Explanation

The Thorium series begins with Thorium-232 ($232 / 4 = 58$) and ends with Lead-208 ($208 / 4 = 52$). Because all mass numbers in the cascade are divisible by 4, it is termed the $4n$ series.