The first ionisation enthalpies of four consecutive elements present in the second period of the periodic table are 8.3, 11.3, 14.5 and 13.6 eV respectively. Which one of the following is the first ionisation enthalpy of nitrogen ?

Options

A. 13.6
B. 14.5
C. 11.3
D. 8.3

Explanation

To determine the first ionization enthalpy of nitrogen from the given values of the first ionization enthalpies of four consecutive elements in the second period of the periodic table, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Elements in the Second Period**:
The elements in the second period of the periodic table are:
- Lithium (Li)
- Beryllium (Be)
- Boron (B)
- Carbon (C)
- Nitrogen (N)
- Oxygen (O)
- Fluorine (F)
- Neon (Ne)

2. **List the Given Ionization Enthalpies**:
The first ionization enthalpies provided in the question are:
- 8.3 eV
- 11.3 eV
- 14.5 eV
- 13.6 eV

3. **Assign the Ionization Enthalpies to the Elements**:
Based on the order of elements in the second period, we can assign the ionization enthalpies as follows:
- 8.3 eV corresponds to Boron (B)
- 11.3 eV corresponds to Carbon (C)
- 14.5 eV corresponds to Nitrogen (N)
- 13.6 eV corresponds to Oxygen (O)

4. **Identify the Ionization Enthalpy for Nitrogen**:
From the assignments made, we see that the first ionization enthalpy for Nitrogen (N) is 14.5 eV.

5. **Conclusion**:
Therefore, the first ionization enthalpy of nitrogen is **14.5 eV**.

### Final Answer:
The first ionization enthalpy of nitrogen is **14.5 eV**.