Assertion: It has been found that for hydrogenation reaction the catalytic activity increases from group5 to group-11 metals with maximum activity being shown by groups 7-9 elements of the periodic table. Reason: For 7-9 group elements adsorption rate is maximum.

Options

A. Both assertion and reason are correct and reason is correct explanation of assertion.
B. Both assertion and reason are correct and reason is not correct explanation of assertion.
C. Assertion is true & reason is false.
D. Both are incorrect

Answer

To solve the question, we need to analyze both the assertion and the reason provided.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that the catalytic activity for hydrogenation reactions increases from group 5 to group 11 metals, with maximum activity observed in groups 7 to 9.
- This means that as we move from group 5 to group 11 in the periodic table, the ability of these metals to act as catalysts in hydrogenation reactions improves, peaking in groups 7 to 9.

2. **Understanding the Reason**:
- The reason provided is that for the elements in groups 7 to 9, the adsorption rate is maximum.
- Adsorption refers to the process by which atoms, ions, or molecules from a gas, liquid, or dissolved solid adhere to a surface. A higher adsorption rate generally leads to better catalytic activity.

3. **Connecting Assertion and Reason**:
- The assertion is supported by the reason. The increase in catalytic activity from group 5 to group 11 can be attributed to the efficiency of adsorption of reactants on the catalyst's surface.
- Since groups 7 to 9 have the highest adsorption rates, it logically follows that these groups would exhibit the maximum catalytic activity.

4. **Conclusion**:
- Both the assertion and the reason are correct.
- Furthermore, the reason provided is a correct explanation for the assertion.

### Final Answer:
Both the assertion and reason are correct, and the reason is the correct explanation of the assertion.