Assertion `(A): gamma-` rays have very high penetrating power.
Reason `(R) : gamma-` rays are high `-` energy electromagnetic radiations.

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 `(A)` is incorrect, but `(R)` is correct.

Explanation

To solve the given question regarding the assertion and reason about gamma rays, we will analyze both statements step by step.

### Step 1: Understand the Assertion
**Assertion (A): Gamma rays have very high penetrating power.**
- Gamma rays are a form of electromagnetic radiation that can penetrate materials more effectively than other types of radiation (like alpha or beta particles). This is due to their high energy and short wavelength.

### Step 2: Understand the Reason
**Reason (R): Gamma rays are high-energy electromagnetic radiations.**
- Gamma rays are indeed high-energy electromagnetic waves. They are produced during radioactive decay of atomic nuclei and have the shortest wavelength in the electromagnetic spectrum, which correlates to their high energy.

### Step 3: Analyze the Relationship
- The reason provided (R) explains why the assertion (A) is true. Since gamma rays are high-energy electromagnetic radiations, they possess the characteristics that allow them to penetrate materials effectively.

### Step 4: Conclusion
- Both the assertion and the reason are correct, and the reason accurately explains the assertion. Therefore, the correct answer is that both the assertion and reason are correct, and the reason is the correct explanation of the assertion.

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

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