Answer:
a) The atomic number decreases by 2 units
b) the atomic mass decreases by 4 units
Step-by-step explanation:
An alpha particle is a helium nucleus, which is why it is made up of two positive protons and two negative neutrons, the mass of the particles is almost the same.
a) The atomic number decreases by 2 units
b) the atomic mass decreases by 4 units