If ` 2g` of an isotope has a half`-` life of 7 days, the half life of `1g` sample is

Options

A. `3.5` days
B. 7 days
C. 14 days
D. 2 days

Explanation

To solve the problem, we need to understand the concept of half-life in radioactive decay. The half-life of a radioactive isotope is the time required for half of the radioactive atoms in a sample to decay.

### Step-by-Step Solution:

1. **Identify the Given Information**:
- We have a sample of 2 grams of an isotope.
- The half-life of this sample is given as 7 days.

2. **Understand the Concept of Half-Life**:
- The half-life of a radioactive substance is a constant property of that substance and does not depend on the amount of the substance present. This means that whether we have 2 grams, 1 gram, or any other amount, the half-life remains the same.

3. **Apply the Concept**:
- Since the half-life is independent of the quantity of the sample, the half-life for 1 gram of the same isotope will also be the same as that for 2 grams.

4. **Conclusion**:
- Therefore, the half-life of a 1 gram sample of the isotope is also 7 days.

### Final Answer:
The half-life of a 1 gram sample is **7 days**.

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