First ionisation potential for copper is higher than that for potassium. The second ionisation potential of copper is

Options

A. Equal to the 2nd ionisation potential of potasium
B. more then the 2 nd ionisation potential of potassium
C. less than the 2nd ionisation potential of potassium
D. less than the 2nd ionisation potential of potassium

Explanation

`Cu:(Z=29) : 1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)4s^(1)3d^(10)`
`K(Z=19): 1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)4s^(1)`
`Cu^(+): 1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)3d^(10)`
`K^(+) : 1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)`
Clearly second ionisation energy of K will be more than Cu because in case of K the second electron is to be removed from fully filled 3rd shell.