Question

The first ionization energy of carbon atom os greter than boron where as the reverse is true for the aecond ionization energy. Explain

Answer 1

yes it is
and it is bcz
when the 1st ionization occurs then according to the rules the ionization energy increases across the periods so
C has greater ionization energy than boron but in case of 2nd ionization energy the electron which has to removed from boron is in 2s susheel which is fully filled so it is difficult to remove it whereas in case of Carbon it has to be removed from the 2p sushell which is neither full filled nor half so it is easier comparatively to that of boron

Answer 2

Answer:

Explanation:

We first need to see the electronic configurations of both boron and carbon.

B:1s2 2s2 2p1

C:1s2 2s2 2p2

First ionisation energy is defined as the energy required to remove the first Valence electron from an atom.

We know,across a period,size decreases, effective nuclear charge increases.

Hence,we need more energy to remove the electron..

So,we can say first ionisation energy is greater for carbon than that of boron.

After removal of electron,see the configuration:

B:1s2 2s2(Fully filled orbitals implying increase in stability)

C:1s2 2s2 2p1

Here,we find in B, orbital is fully filled after removing first electron.This signifies increase in exchange energy amongst the paired electrons leading to stability.

So,in case of second ionisation energy,B has larger value.This comes under an exception, owing to the stability due to fully filled orbitals.

Key point: Always remember, whenever you encounter an element having half filled or fully filled orbitals,they will have more stability and lesser ionisation potential.

Hope you understood.