Elements with their electronic configurations are given below: Answer the following questions:
(I) `1s^(2) 2s^2 (II) 1s^(2) 2s^(2) 2p^(6) (III) 1s^(2) 2s^(2) 2p^(6) 3s^(2) (IV) 1s^(2) 2s^(2) 2p^(3) (V) 1s^(2) 2s^(2) 2p^(5)`
The element with lowest value of electron affinity is:

Options

A. I
B. II
C. III
D. IV

Explanation

To determine which element has the lowest value of electron affinity among the provided electronic configurations, we need to analyze each configuration based on their stability and tendency to gain an electron.

### Step-by-Step Solution:

1. **Identify the Elements:**
- (I) `1s^2 2s^2` - This configuration corresponds to Beryllium (Be).
- (II) `1s^2 2s^2 2p^6` - This configuration corresponds to Neon (Ne).
- (III) `1s^2 2s^2 2p^6 3s^2` - This configuration corresponds to Magnesium (Mg).
- (IV) `1s^2 2s^2 2p^3` - This configuration corresponds to Phosphorus (P).
- (V) `1s^2 2s^2 2p^5` - This configuration corresponds to Fluorine (F).

2. **Understanding Electron Affinity:**
- Electron affinity is the energy change that occurs when an electron is added to a neutral atom in the gas phase. A higher (more negative) electron affinity indicates that an atom is more likely to gain an electron.

3. **Analyze the Stability of Configurations:**
- Elements with full or half-full subshells are generally less likely to gain additional electrons due to their stability.
- (I) Be has a full 2s subshell and is unlikely to gain an electron.
- (II) Ne has a full outer shell (2s and 2p) and will not gain an electron.
- (III) Mg has a full 2p subshell and a full 3s subshell, making it stable and less likely to gain an electron.
- (IV) P has a half-filled 2p subshell (2p^3), which is relatively stable but can gain an electron.
- (V) F has a configuration of 2p^5, which is one electron short of a full p subshell (2p^6) and is very likely to gain an electron.

4. **Determine the Lowest Electron Affinity:**
- Since Be, Ne, and Mg are stable and less likely to gain electrons, they will have low electron affinities.
- Among these, Neon (Ne) has the lowest electron affinity because it is a noble gas and does not readily accept electrons.
- Phosphorus (P) and Fluorine (F) can gain electrons, but Fluorine has a high electron affinity due to its tendency to complete its p subshell.

5. **Conclusion:**
- The element with the lowest value of electron affinity is **Neon (Ne)**, corresponding to configuration (II) `1s^2 2s^2 2p^6`.

### Final Answer:
The element with the lowest value of electron affinity is Neon (Ne) with the configuration `1s^2 2s^2 2p^6`.