Question

First ionisation potential of c-atom is greater than that of B atom , where as the reverse is true is for second ionisation potential

Answer 1

Answer:

First,we should take a look at the electronic configurations of both the atoms.

C - 1s^2 , 2s^2, 2p^2

B - 1s^2, 2s^2,2p^1

The answer to the first question is very simple.The size of a carbon atom is smaller than boron.So the Valence electron of carbon faces a greater nuclear force( nuclear charge) than that of boron.In order to break that,carbon needs greater energy ,hence the first I.E of carbon is higher.

Coming to the second question, let's take a look at the electronic configurations of the atoms again but now without an electron.

C - 1s^2, 2s^2,2p^1

B - 1s^2 , 2s^2

Boron has a fully filled orbital (2s2) than carbon(2p1). And since, fully filled orbitals have more stability than partially filled orbitals so greater amount of energy will be needed to remove an electron from boron.So in this case, the second I.E of boron is higher than that of carbon.