Chemistry - CHEMICAL BONDING Question with Solution | TestHub

Electronic configuration for chromium is : $${}_{24}\mathrm{Cr}\to 1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{5}4s^1$$ After ionisation of $4s$ electron the next electron which will be ionised is from $3d$ orbital. As $3d^5$ electronic configuration, is stable, hence, the second ionisation of $\mathrm{Cr}$ will require much greater ionisation energy than the expected one.