Question

Which set of elements shows positive electron gain enthalpy?
(1) He, N, O
(2) Ne, N, CI
(3) O, CIF
(4) N, He, Ne​

Answer 1

Answer: Option (4) is the correct answer.

Explanation:

A positive electron gain enthalpy is defined as the energy required to enter an electron into an atom.

This means that when an element has completely filled orbital then it will be not be able to accept an electron easily. Hence, we need to supply heat energy to it in order to make it accept an electron.

This shows that element will have a positive gain enthalpy.

For example, both He and Ne are noble gases and it won't accept an electron easily. So, they will have positive electron gain enthalpy.

On the other hand, electronic configuration of nitrogen is $1s^{2}2s^{2}2p^{3}$.

As it has half-filled p-orbital so, it is stable in nature. Therefore, to add an electron into it's p-orbital will require high heat energy.

Hence, nitrogen will have positive electron gain enthalpy.

Thus, we can conclude that the set N, He, Ne​ elements shows positive electron gain enthalpy.

Answer 2

Answer: Option (4) is the correct answer.

Explanation:

A positive electron gain enthalpy is defined as the energy required to enter an electron into an atom.

This means that when an element has completely filled orbital then it will be not be able to accept an electron easily. Hence, we need to supply heat energy to it in order to make it accept an electron.

This shows that element will have a positive gain enthalpy.

For example, both He and Ne are noble gases and it won't accept an electron easily. So, they will have positive electron gain enthalpy.

On the other hand, electronic configuration of nitrogen is 1s^{2}2s^{2}2p^{3}1s

2

2s

2

2p

3

.

As it has half-filled p-orbital so, it is stable in nature. Therefore, to add an electron into it's p-orbital will require high heat energy.

Hence, nitrogen will have positive electron gain enthalpy.

Thus, we can conclude that the set N, He, Ne elements shows positive electron gain enthalpy.