alpha particle = 4He2

if alpha particle release them mass will decrease by 4 and atomic number decrease by 2

234U ---> 230Th + 4He

part b ) e- = 0H-1 it increase the atomic number by +1

32P --- > 32S + 0H-1

part c ) positron decay , 0H+1

30P15 ---> 30Si14 + 0H+1

part d )

gamma decay doesnot in mass and atomic number

24Mg ----> 24mg + gamma