Select the correct statement `(s)`

Options

A. On Pauling scale, the difference in `EN` of two atoms `A` and `B` in `SI` units is.
`(EN_(A)-EN_(B))=0.1017 sqrt(Delta_(A-B))`.
B. On Pauling scale, the difference in `EN` of two atoms `A` and `B` in `kcal mol^(-1)` is.
`(EN_(A)-EN_(B))=0.208 sqrt(Delta_(A-B))`.
C. The Mulliken's `EN` values are scaled down to match the Pauling
value by dividing `
((IP+EA)/(2))` in `eV` by `2.8`.
D. The Maulliken's `EN` values are scaled down to match the Pauling
value by multiplying `
((IP+EA)/(2))` in `eV` by `3.17`

Answer

To solve the question of selecting the correct statements regarding electronegativity, we will analyze each statement based on the information provided in the video transcript.

### Step-by-Step Solution:

1. **Understanding Electronegativity Scales**:
- Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons.
- Two common scales for measuring electronegativity are the Pauling scale and the Mulliken scale.

2. **Pauling Scale**:
- The Pauling scale relates the difference in electronegativity (χ) to bond dissociation energies.
- The formula given in the transcript for the Pauling scale in SI units (kJ/mol) is:
\[ \chi_A - \chi_B = 0.1017 \sqrt{\Delta} \]
- In kilocalories per mole, the formula is:
\[ \chi_A - \chi_B = 0.208 \sqrt{\Delta} \]
- Both statements regarding the Pauling scale are correct.

3. **Mulliken Scale**:
- The Mulliken scale defines electronegativity as the average of ionization energy (I) and electron affinity (EA):
\[ \chi_A = \frac{I + (-EA)}{2} = \frac{I - EA}{2} \]
- This means that Mulliken's electronegativity is based on the average of these two values.

4. **Comparison of Scales**:
- The transcript states that Mulliken values are approximately 2.8 times larger than Pauling values. Therefore, to convert Mulliken values to Pauling values, you would divide by 2.8.

5. **Evaluating the Statements**:
- **Statement 1**: Correct (Pauling scale in SI units).
- **Statement 2**: Correct (Pauling scale in kilocalories).
- **Statement 3**: Correct (Mulliken values scaled down by dividing by 2.8).
- **Statement 4**: Incorrect (Mulliken values are not scaled down by multiplying).

### Conclusion:
The correct statements are **1, 2, and 3**.

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