When a nucleus emits an alpha particle, its ____

1. A Option A: mass number is unchanged and atomic number rises by 1
2. B Option B: mass number falls by 4 and atomic number by 2
3. C Option C: mass number falls by 2 and atomic number by 4
4. D Option D: mass number rises by 4 and atomic number by 2

Answer checked 11 October 2026 · How we write and check questions