Which of the following statements is true about electronegativity?

Options

A. Electronegativity of an element depends upon its effective nuclear charge
B. Electronegativity of a cation is proportional to charge on the cation
C. Electronegativity increases as the s-character in hybrid orbital increases
D. Electronegativity of a anion is proportiona to charge on the anion

Answer

To determine which statements about electronegativity are true, we will analyze each statement provided in the question step by step.

### Step 1: Understanding Electronegativity
Electronegativity is defined as the tendency of an atom to attract shared electrons in a chemical bond. The greater the electronegativity, the stronger the atom's ability to attract electrons towards itself.

**Hint:** Remember that electronegativity is about the attraction of electrons in a bond.

### Step 2: Analyzing the Statements
Now, let's evaluate each of the statements provided:

1. **Electronegativity of an element depends upon its effective nuclear charge.**
- **True.** The effective nuclear charge is the net positive charge experienced by an electron in a multi-electron atom. A higher effective nuclear charge means a stronger attraction between the nucleus and the electrons, leading to higher electronegativity.

**Hint:** Consider how the number of protons (positive charge) affects the attraction of electrons.

2. **Electronegativity of a cation is proportional to the charge on the cation.**
- **True.** When a cation is formed, it loses electrons. With fewer electrons than protons, the effective nuclear charge increases, which enhances its ability to attract electrons, thus increasing its electronegativity.

**Hint:** Think about how losing electrons affects the attraction between the nucleus and the remaining electrons.

3. **Electronegativity increases as the s character in the hybrid orbital increases.**
- **True.** The s orbital is closer to the nucleus than the p orbital. Therefore, hybrid orbitals with a higher s character (like sp) will have a stronger attraction for electrons compared to those with less s character (like sp3).

**Hint:** Recall the relationship between orbital types and their proximity to the nucleus.

4. **Electronegativity of an anion is proportional to the charge of the anion.**
- **False.** An anion has gained electrons, which increases electron-electron repulsion. This makes it less effective at attracting additional electrons, thus reducing its electronegativity.

**Hint:** Consider how gaining electrons affects the ability to attract more electrons.

### Step 3: Conclusion
Based on the analysis, the true statements about electronegativity are:
- The electronegativity of an element depends on its effective nuclear charge.
- The electronegativity of a cation is proportional to the charge on the cation.
- The electronegativity increases as the s character in the hybrid orbital increases.

The false statement is:
- The electronegativity of an anion is proportional to the charge of the anion.

Thus, the correct options are statements 1, 2, and 3.

**Final Answer:** The true statements about electronegativity are 1, 2, and 3.