In what way is the electronic configuration of the transition elements different from that of the nontransition elements ?

Explanation

Transition elements have partially filled d - subshell in the penultimate shell [with electronic configuration `(n-1)d^(1-10)ns^(0-2)`], whereas non - transition elements do not have any partially filled d - subshell in the penultimate shell [outer electronic configuration : `ns^(1-2)` or `ns^(2)np^(2)np^(1-6)`]. Consequently in transition elements the last electron enters the d - subshell of penultimate shell, whereas in non - transition elements the last electron enters the s or p - subshell of outermost shell.