Electronic configuration of the given elements arc Mn→1s22s22p63s23p63d54s2 Cr→1s22s22p63s23p63d54s1 Ti→1s22s22p63s23p63d24s2 V→1s22s22p63s23p63d34s2 In general, ionization potential (both 1st and 2nd) increases from left to right across the period due to increase in effective nuclear charge. On this basis, the second IP values should exhibit the trend: Mn > Cr > V > Ti But the actual observed order is: Cr > Mn > V > Ti Practically, only chromium is exceptional and rest others show the normal trend. This exceptional behavior of chromium is (3d5) that it achieves after the loss of first electron.due to the stable configuration