Question

If $E_n$ is the energy required to remove the $n^{th}$ electron form the outer most shell of carbon then decreasing order of the energies is:

• A. $E_4$
• B. $E_3$
• C. $E_2$
• D. $E_1$

Answer 1

It is easier to knock off the first electron in the outermost shell than knocking off the rest. More the number of electrons pulled out, higher is the nuclear pull on the remaining electrons, hence, more is the energy required to remove them. Hence the decreasing order order will be $E_1$ < $E_2$ < $E_3$ < $E_4$.