Assertion(A): Helium diffuses through most commonly used laboratory materials.
Reason(R): This gas has a very low melting point.

Options

A. Both A and R are true and R is the correct explanation of A
B. Both A and R are true but R is NOT the correct explanation of A
C. A is true but R is false
D. A is false and R is True.

Explanation

To analyze the given statements, let's break down the assertion and reason step by step.

### Step 1: Evaluate the Assertion (A)
**Assertion (A): Helium diffuses through most commonly used laboratory materials.**

- Helium is a noble gas with a very small atomic size and low molecular weight (4 g/mol).
- Due to its small size and low molecular weight, helium can easily pass through tiny pores in materials, making it capable of diffusing through many laboratory materials.
- Therefore, the assertion is **correct**.

### Step 2: Evaluate the Reason (R)
**Reason (R): This gas has a very low melting point.**

- Helium indeed has a very low melting point (around -272°C or 1 K), but this property is not the reason for its ability to diffuse through materials.
- The ability of a gas to diffuse is primarily related to its molecular weight and size rather than its melting point.
- In fact, noble gases generally have high melting and boiling points compared to other gases, but this does not directly correlate with diffusion.
- Therefore, the reason is **incorrect**.

### Step 3: Conclusion
- Since the assertion is correct and the reason is incorrect, the correct relationship between the two statements is that the assertion is true, but the reason is false.

### Final Answer
The correct option is that the assertion is true, and the reason is false.

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