Assertion `(A) :` Protons are better projectiles than neutrons.
Reason `(R) :` The neutrons being neutral do not experience repulsion from positively charged nucleus.

Options

A. If both `(A)` and `(R)` are correct , and `(R)` is the correct explanation of `(A)`
B. If both `(A)` and `(R)` are correct, but (R) is not the correct explanation of `(A)`
C. If `(A)` is correct, but `(R)` is incorrect.
D. If both `(A)` and `(R)` are incorrect.

Answer

To analyze the assertion and reason provided in the question, let's break it down step by step.

### Step 1: Understand the Assertion
The assertion states that "Protons are better projectiles than neutrons."

- **Explanation**: Protons are positively charged particles. When they approach the nucleus of an atom, they experience repulsion due to the presence of other positively charged protons in the nucleus. This repulsion can hinder their ability to penetrate the nucleus effectively.

### Step 2: Understand the Reason
The reason states that "Neutrons being neutral do not experience repulsion from positively charged nucleus."

- **Explanation**: Neutrons are neutral particles and do not carry any charge. Therefore, when they approach the nucleus, they do not experience any electrostatic repulsion from the positively charged protons in the nucleus. This allows them to penetrate the nucleus more effectively compared to protons.

### Step 3: Compare the Assertion and Reason
- Since protons face repulsion from the positively charged nucleus, they are not as effective as projectiles when it comes to penetrating the nucleus.
- Neutrons, on the other hand, can penetrate the nucleus without facing any repulsion due to their neutral charge.

### Conclusion
Based on the analysis:
- The assertion that "Protons are better projectiles than neutrons" is **incorrect**.
- The reason that "Neutrons being neutral do not experience repulsion from positively charged nucleus" is **correct**.

### Final Answer
- **Assertion (A)**: Incorrect
- **Reason (R)**: Correct