Which of the following is incorrect ?

Options

A. With increase in atomic size, ionisation energy increases
B. With increase in atomic size, electron affinity increases
C. With increase in atomic size, metallic character increases
D. With increase in atomic size, electronegativity increases

Answer

To solve the question "Which of the following is incorrect?", we will analyze each statement provided in the question based on our understanding of atomic size, ionization energy, electron affinity, and metallic character.

### Step 1: Analyze the first statement
**Statement:** With increase in atomic size, ionization energy increases.

**Analysis:**
- Atomic size and ionization energy are inversely proportional. As atomic size increases, the outermost electrons are farther from the nucleus, which makes them easier to remove. Therefore, ionization energy decreases with an increase in atomic size.
- **Conclusion:** This statement is **incorrect**.

### Step 2: Analyze the second statement
**Statement:** With increase in atomic size, electron affinity increases.

**Analysis:**
- Electron affinity generally decreases with an increase in atomic size. Larger atoms have their outer electrons further from the nucleus, which makes it less favorable for them to gain an electron.
- **Conclusion:** This statement is **incorrect**.

### Step 3: Analyze the third statement
**Statement:** With increase in atomic size, metallic character increases.

**Analysis:**
- Metallic character increases down a group in the periodic table due to the increase in atomic size and the tendency to lose electrons. Therefore, this statement is correct as larger atoms tend to be more metallic.
- **Conclusion:** This statement is **correct**.

### Step 4: Analyze the fourth statement
**Statement:** With increase in atomic size, electronegativity increases.

**Analysis:**
- Electronegativity generally decreases with an increase in atomic size. Larger atoms have a weaker attraction for electrons because their outer electrons are further from the nucleus.
- **Conclusion:** This statement is **incorrect**.

### Final Conclusion:
The incorrect statements are:
1. With increase in atomic size, ionization energy increases. (Incorrect)
2. With increase in atomic size, electron affinity increases. (Incorrect)
4. With increase in atomic size, electronegativity increases. (Incorrect)

The only correct statement is the third one regarding metallic character.

### Summary of Incorrect Statements:
- The incorrect statements are 1, 2, and 4.