Choose the incorrect statements from the following:

Options

A. Ionization energy of atom may be negative.
B. Ionization energy of an ion may be negative.
C. Ionization energy is inverscly proportional to radius.
D. Electron present in p orbital is in need of less energy for its removal as compared to electron present in d orbital having the same principal quantum number.

Answer

To solve the question of identifying the incorrect statements regarding ionization energy, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Understanding Ionization Energy**:
- Ionization energy is defined as the energy required to remove the outermost electron from an atom or ion in its gaseous state.

2. **Analyzing Statement 1**:
- **Statement**: "Ionization energy of atom may be negative."
- **Analysis**: Ionization energy cannot be negative because it represents energy required to remove an electron. Therefore, this statement is incorrect.

3. **Analyzing Statement 2**:
- **Statement**: "Ionization energy of an ion may be negative."
- **Analysis**: Similar to the first statement, ionization energy cannot be negative for ions either. It always requires energy to remove an electron. Thus, this statement is also incorrect.

4. **Analyzing Statement 3**:
- **Statement**: "Ionization energy is inversely proportional to radius."
- **Analysis**: This statement is correct. As the atomic radius increases, the outermost electron is further from the nucleus, resulting in a weaker attraction and lower ionization energy.

5. **Analyzing Statement 4**:
- **Statement**: "Electron present in P orbital is in need of less energy for its removal as compared to electron present in D orbital having the same principal quantum number."
- **Analysis**: This statement is incorrect. Electrons in the D orbital are generally further from the nucleus and experience less effective nuclear charge compared to P orbital electrons. Therefore, removing an electron from a D orbital requires less energy than from a P orbital. Thus, this statement is also incorrect.

### Conclusion:
The incorrect statements are:
- Statement 1: "Ionization energy of atom may be negative."
- Statement 2: "Ionization energy of an ion may be negative."
- Statement 4: "Electron present in P orbital is in need of less energy for its removal as compared to electron present in D orbital having the same principal quantum number."

### Final Answer:
The incorrect statements are 1, 2, and 4.

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