Answer
Ruthenium
Work Step by Step
Ground state electronic configuration of Ruthenium is:
$[Kr] 4d^{7} 5s^{1}$
It loses one electron from 5s and one electron from 4d subshell to attain a charge of +2. Electronic configuration of $Ru^{2+}$ ion is:
$[Kr] 4d^{6}$