`A=1s^(2)2s^(2)2p^(4) B=1s^(2)2s^(2)2p^(5)`
`C=1s^(2)2s^(2)2p^(6)`
(One of A/B/C is neutral atoms)
A,B&C are atoms/anion of same element.
Then incorrect is :-

Options

A. `B_(g)+e^(-)toC_(g)` is exothermic
B. `A_(g)toA_(g)^(+)+e^(-)` is exothermic
C. `C_(g)toA_(g)+2e` is exothermic
D. `B_(g)toA_(g)+e^(-)` is exothermic

Answer

To determine which of the atoms A, B, or C is a neutral atom, we need to analyze their electron configurations and understand the concepts of ionization energy and electron affinity.

### Step-by-Step Solution:

1. **Identify Electron Configurations**:
- Atom A: \(1s^2 2s^2 2p^4\)
- Atom B: \(1s^2 2s^2 2p^5\)
- Atom C: \(1s^2 2s^2 2p^6\)

2. **Determine the Number of Electrons**:
- For Atom A: \(2 + 2 + 4 = 8\) electrons
- For Atom B: \(2 + 2 + 5 = 9\) electrons
- For Atom C: \(2 + 2 + 6 = 10\) electrons

3. **Identify the Element**:
- The electron configuration \(1s^2 2s^2 2p^6\) corresponds to Neon (Ne), which is a noble gas and has a complete outer shell.
- Atom A with 8 electrons corresponds to Oxygen (O) in its anionic form (O\(^{2-}\)).
- Atom B with 9 electrons corresponds to Fluorine (F) in its anionic form (F\(^{-}\)).

4. **Determine Neutral Atom**:
- The neutral atom must have the same number of electrons as the atomic number of the element.
- Atom C (10 electrons) is the neutral atom (Ne).
- Atom A (8 electrons) and Atom B (9 electrons) are anions of the same element.

5. **Analyze Ionization and Electron Affinity**:
- When a neutral atom gains an electron (like going from A to B), it is an exothermic process (releases energy).
- When an anion loses an electron (like going from C to A), it is an endothermic process (absorbs energy).

6. **Identify Incorrect Statement**:
- The incorrect statement would be any assertion that contradicts the established facts about the electron configurations, their corresponding elements, and the nature of the processes (exothermic vs. endothermic).

### Conclusion:
The incorrect statement is related to the nature of the processes when moving between these configurations, particularly regarding whether they are exothermic or endothermic.