Which of the following electrons configruations of an atom has the lowest ionisaytion enthalpy ?

Options

A. `1s^(2),2s^(2)2p^(5)`
B. `1s^(2), 2s^(2)2p^(3)`
C. `1s^(2), 2s^(2), 2p^(2),3s^(1)`
D. `1s^(2), 2s^(2) 2p^(6)`

Answer

C

Explanation

The electronic configuration `1s^(2),2s^(2),2p^(2),3s^(1)` shows lowest ionistable energy because this configuration is unstable due to the presence fo for electron is s-orbital. Hence,less energy is required to remove the electron.