Which one of the following pairs, atoms is most likely to form an ionic bond?

Options

A. Na and CI
B. C and F
C. N and F
D. O and F

Explanation

To determine which pair of atoms is most likely to form an ionic bond, we need to analyze the options based on their electronic configurations and tendencies to gain or lose electrons.

### Step-by-Step Solution:

1. **Understanding Ionic Bonds**: Ionic bonds are formed when one atom transfers electrons to another atom. Typically, this occurs between a metal (which tends to lose electrons) and a non-metal (which tends to gain electrons).

2. **Evaluating the Options**: We will evaluate each pair of atoms provided in the options to see which one is most likely to form an ionic bond.

3. **Option A: Sodium (Na) and Chlorine (Cl)**:
- **Electronic Configuration**:
- Sodium (Na): 2, 8, 1
- Chlorine (Cl): 2, 8, 7
- **Analysis**: Sodium has one electron in its outer shell and can easily lose this electron to achieve a stable configuration (2, 8). Chlorine needs one more electron to complete its octet (2, 8, 8). Therefore, Na will lose one electron to become Na⁺, and Cl will gain one electron to become Cl⁻. This results in the formation of an ionic bond between Na⁺ and Cl⁻.

4. **Option B: Carbon (C) and Fluorine (F)**:
- **Electronic Configuration**:
- Carbon (C): 2, 4
- Fluorine (F): 2, 7
- **Analysis**: Carbon would need to either gain 4 electrons or lose 4 electrons to achieve a stable configuration, which is not feasible. Instead, carbon shares electrons with fluorine, resulting in a covalent bond.

5. **Option C: Nitrogen (N) and Fluorine (F)**:
- **Electronic Configuration**:
- Nitrogen (N): 2, 5
- Fluorine (F): 2, 7
- **Analysis**: Nitrogen can share electrons with fluorine to achieve a stable configuration. This results in a covalent bond rather than an ionic bond.

6. **Option D: Oxygen (O) and Fluorine (F)**:
- **Electronic Configuration**:
- Oxygen (O): 2, 6
- Fluorine (F): 2, 7
- **Analysis**: Both oxygen and fluorine are electronegative and would prefer to share electrons rather than transfer them, leading to a covalent bond.

7. **Conclusion**: Among the given options, the pair that is most likely to form an ionic bond is **Sodium (Na) and Chlorine (Cl)**, as sodium can lose an electron and chlorine can gain an electron, leading to the formation of Na⁺ and Cl⁻ ions.

### Final Answer:
**Sodium (Na) and Chlorine (Cl)** are most likely to form an ionic bond.