Which statement below is TRUE of the mass number of the daughter atom that is produced during alpha decay?

Question

a
The mass number of the daughter atom is 2 less than the parent atom.
b
The mass number of the daughter atom is 4 more than the parent atom.
c
The mass number of the daughter atom is 4 less than the parent atom.
d
The mass number of the daughter atom is 2 more than the parent atom.

Answer 1

a. The mass number of the daughter atom is 2 less than the parent atom.