Which of the following has higher IP ?

Options

A. Oxygen
B. Sulphur
C. Selenium
D. Tellurium

Answer

To determine which of the given elements has the highest ionization potential (IP), we will analyze the elements in the context of their positions in the periodic table and the trends in ionization energy.

### Step-by-Step Solution:

1. **Identify the Elements**: The elements given are oxygen (O), sulfur (S), selenium (Se), and tellurium (Te). All these elements belong to Group 16 of the periodic table.

2. **Understand Ionization Potential**: Ionization potential (or ionization energy) is the energy required to remove an electron from an atom in its gaseous state. Higher ionization potential means it is more difficult to remove an electron.

3. **Recognize the Trend in Group 16**: In Group 16, as we move down the group from oxygen to tellurium, the atomic size increases. This increase in atomic size is due to the addition of electron shells.

4. **Effect of Atomic Size on Ionization Energy**: As atomic size increases, the distance between the nucleus and the outermost electrons also increases. This results in a weaker attraction between the nucleus and the outermost electrons, making it easier to remove an electron. Therefore, ionization energy decreases down the group.

5. **Compare the Elements**:
- **Oxygen (O)**: Smallest atomic size in the group, highest attraction between nucleus and outermost electron, thus highest ionization energy.
- **Sulfur (S)**: Larger than oxygen, lower ionization energy than oxygen.
- **Selenium (Se)**: Larger than sulfur, lower ionization energy than sulfur.
- **Tellurium (Te)**: Largest in the group, lowest ionization energy.

6. **Conclusion**: Since oxygen has the smallest atomic size and the highest attraction between the nucleus and its outermost electron, it has the highest ionization potential among the given elements.

### Final Answer:
The element with the highest ionization potential is **Oxygen (O)**.

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