When a radioactive element undergoes an alpha disintegration, both the atomic weight and the atomic number of?

Question

the daughter nucleus__________.
ex) increase, decrease, remain the same..
why?

Answer 1

Decrease.

An alpha particle is a helium nucleus (two protons and two neutrons). So, the loss of an alpha particle decreases the atomic weight by about 4, and the atomic number (number of protons) by 2.