Neptunium-237 decays by a series of steps to bismuth-209. How many α and β particles are produced by this decay process?

Verified step by step guidance

1. Step 1: Understand the decay process. Neptunium-237 (Np-237) decays to Bismuth-209 (Bi-209) through a series of alpha (α) and beta (β) decays. An alpha decay reduces the atomic number by 2 and the mass number by 4, while a beta decay increases the atomic number by 1 without changing the mass number.
2. Step 2: Determine the change in mass number. The initial mass number is 237 (for Np-237) and the final mass number is 209 (for Bi-209). Calculate the total change in mass number: 237 - 209 = 28.
3. Step 3: Calculate the number of alpha decays. Each alpha decay reduces the mass number by 4. Divide the total change in mass number by 4 to find the number of alpha decays: 28 / 4 = 7 alpha decays.
4. Step 4: Determine the change in atomic number. The initial atomic number of Neptunium is 93, and the final atomic number of Bismuth is 83. Calculate the total change in atomic number: 93 - 83 = 10.
5. Step 5: Calculate the number of beta decays. Each alpha decay reduces the atomic number by 2, so 7 alpha decays reduce it by 14. To reach a total change of 10, beta decays must increase the atomic number by 4. Therefore, 4 beta decays are needed.