Why it is easier to remove a 2p electron from an oxygen atom than from a nitrogen atom?

The electrons in oxygen are paired while in nitrogen, they are not.

Explanation:

To analyse this we start with writing out the ground state electronic configurations for both elements.

Oxygen: 1s²2s²2p4 meaning the p subshell has the following arrangement of electrons                  ↑↓   ↑   ↑

Nitrogen : 1s²2s²2p³ meaning the p subshell has the following arrangement of electrons  ↑    ↑    ↑

Clearly the paired electron in oxygen will be experiencing repulsion from the electron it shares an orbital with causing it to be removed easily. The electrons in nitrogen are unpaired, each orbital is singly occupied

1 a

2 b

3 b

4 d

5 d

6 d

explanation:

no sign of dia of fuel cell