What is the name given to elements with same mass number and different atomic number ?

Arrange the α, β and γ radiations in ascending order of their (i) ionizing power, and (ii) penetrating power.

A certain radioactive nucleus emits a particle that leaves it's mass number unchanged, but increases it's atomic number by one. Identify the particle and write it's symbol.

What happens to the (i) atomic number, (ii) mass number of the nucleus of an element when (a) an α particle, (b) a β particle, and (c) γ radiation, is emitted?