What happens to the position of an element in the periodic table when it's nucleus emits (a) an α particle, (b) a β particle and (c) γ radiation? Give reason for your answer.

When the nucleus of an element emits an α particle, the position of the resultant element changes to two places earlier (i.e., to the left of the parent element in the periodic table).

This happens because the atomic number decreases by 2, hence the new element shifts two places to the left on emission of an α particle.

(b) When the nucleus of an element emits a β particle, the position of the resultant element changes to one place after (i.e., one place to the right ).

This happens because the atomic number increases by 1, hence the new element shifts one place to the right on emission of a β particle.

(c) When the nucleus of an element emits a γ radiation, there is no change in the position of the element in the periodic table.

This happens because there is no change in the atomic number, hence there is no change in the position of the element on emission of γ radiations.