Assertion:- The heavier P-block elements form storng `pi-` bonds.
Reasons:- The heavier elements of p-block form `dpi-p pi` or `dpi-dpi` bonds.

Answer

To analyze the assertion and reason provided in the question, we will break down the concepts related to the bonding in heavier p-block elements step by step.

### Step 1: Understanding the Assertion
The assertion states that "The heavier P-block elements form strong π bonds."

- **Explanation**: Heavier p-block elements, such as sulfur, selenium, and tellurium, have the ability to form π bonds. However, the strength of these π bonds can vary based on the type of orbital overlap involved.

### Step 2: Understanding the Reason
The reason states that "The heavier elements of p-block form \(d\pi-p\pi\) or \(d\pi-d\pi\) bonds."

- **Explanation**: In heavier p-block elements, there are available d-orbitals that can participate in bonding. This allows for the formation of \(d\pi-p\pi\) and \(d\pi-d\pi\) bonds, which are different from the \(p\pi-p\pi\) bonds formed by lighter p-block elements like oxygen.

### Step 3: Comparing Bond Strengths
Now, we need to compare the strength of these different types of bonds.

- **Bond Strength**:
- \(p\pi-p\pi\) bonds (formed by lighter elements) are generally stronger due to better overlap between the p-orbitals.
- \(d\pi-p\pi\) and \(d\pi-d\pi\) bonds (formed by heavier elements) are generally weaker because the overlap between d-orbitals and p-orbitals is not as effective as that between p-orbitals.

### Step 4: Conclusion
Based on the analysis:
- The assertion that heavier p-block elements form strong π bonds is **false**.
- The reason that heavier elements of the p-block form \(d\pi-p\pi\) or \(d\pi-d\pi\) bonds is **true**.

Thus, the final conclusion is:
- **Assertion is false; Reason is true.**

### Summary of the Solution
1. The assertion is incorrect because heavier p-block elements do not form strong π bonds.
2. The reason is correct as it explains the type of bonds formed by heavier p-block elements.