Why do some of the periodic properties like
atomic size, electronegativty and ionisation
potential of transition and inner transition
elements not show as much variation as the
representative elements?

Explanation

(i) shell into which the differentiating electron enters
(ii) general electronic configuration of representative
elements
(iii) comparison with general electronic configurations
of transition and inner transition elements
(iv) comparison of effective nuclear charge and its
effect on the periodic properties