Answer:
1.Fluorine is having 7 number of electrons and 1 makes bond.
 Electronic configuration - 1S² 2S² 2P⁵ 
 1 electron need to get in stable states 2P⁶.
2.Oxygen is having 6 balance electron and 2 makes bonds.
 Electronic configuration - 1S² 2S² 2P⁴ 
 2 electron need to get in stable states 2P⁶.
3.Nitrogen is having 5 balance electron and 3 makes bonds.
 Electronic configuration - 1S² 2S² 2P³ 
 3 electron need to get in stable states 2P⁶.
4. Carbon having 4 balance electron and 4 makes bonds.
 Electronic configuration - 1S² 2S² 2P²
 4 electron need to get in stable states 2P⁶.