Which sequence of ionisation potential is correct?

Options

A. `B lt Be `
B. `Be lt B `
C. `Be = B `
D. None of these

Answer

To determine the correct sequence of ionization potentials for the elements Beryllium (Be) and Boron (B), we need to analyze the concept of ionization potential and how it varies across the periodic table.

### Step-by-Step Solution:

1. **Understanding Ionization Potential**:
Ionization potential (or ionization energy) is the energy required to remove an electron from a neutral atom in its gaseous state.

2. **Position in the Periodic Table**:
- Beryllium (Be) is located in Group 2 (alkaline earth metals) and Period 2 of the periodic table.
- Boron (B) is located in Group 13 and also in Period 2.

3. **Trend of Ionization Potential**:
- As we move from left to right across a period in the periodic table, the ionization potential generally increases. This is due to the increase in nuclear charge (more protons in the nucleus) which attracts the electrons more strongly, making them harder to remove.

4. **Comparison of Be and B**:
- Since Beryllium is to the left of Boron in the periodic table, we can conclude that Beryllium will have a higher ionization potential than Boron.
- Therefore, the correct relationship is:
\[ \text{Ionization Potential of Be} > \text{Ionization Potential of B} \]

5. **Evaluating the Options**:
- The options provided are:
1. Be < B (Incorrect)
2. Be > B (Correct)
3. Be = B (Incorrect)
4. None of these (Incorrect)
- The correct answer is option 2: Be > B.

### Final Answer:
The correct sequence of ionization potential is:
**Be > B**.