An atom has electronic configuration `1s^(2) 2s^(2) 2p^(6) 3s^(2) 3P^(6) 3d^(3) 4s^(2)` . In which group wouold it be placed ?

Options

A. fifth group
B. fifteenth group
C. second group
D. third group

Answer

A

Explanation

The amount of energy required to remove an electron from the outermost orbit of a gaseous atom is known as ionisation potential. Elements having half-filled or completely filled orbitals are more stable than partially filled orbitals.
In a period from left to right ionisation potential decreases as the atomic number increases. The given elements (Be, B, C, N, 0) are present in II period as.
Be, B , C , N , O
`overset("Ionisation potential increases")to`
But in cases of Be and B, Be has higher ionisation potential due to stable configuration.

In the same way in cases of N and O, N has higher ionisation potential than O due to stable configuration

So, the correct order of increasing ionisation potential will be
`B lt Be lt C lt O lt N`