When a radioactive substance is subjected to a vacuum, the rate of disintegration per second

Explanation

To solve the question regarding the effect of a vacuum on the rate of disintegration of a radioactive substance, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Radioactive Disintegration:**
- Radioactive disintegration refers to the process by which unstable atomic nuclei lose energy by emitting radiation. This process is random and occurs at a characteristic rate for each radioactive isotope.

2. **Identify the Factors Affecting Disintegration Rate:**
- The rate of disintegration (or decay rate) is primarily dependent on the number of radioactive atoms present in the sample. This is described by the decay constant (λ), which is unique to each radioactive isotope.

3. **Consider the Role of the Medium:**
- The medium in which the radioactive substance is placed (air, vacuum, water, etc.) does not influence the intrinsic rate of disintegration. The decay process is a nuclear reaction that occurs independently of external conditions like pressure or the presence of other materials.

4. **Evaluate the Effect of a Vacuum:**
- When a radioactive substance is placed in a vacuum, the absence of air or other gases does not change the number of radioactive atoms present. Therefore, the rate of disintegration remains constant.

5. **Conclusion:**
- The rate of disintegration per second of a radioactive substance subjected to a vacuum is not affected. It remains the same as it would be in any other medium.

### Final Answer:
The rate of disintegration per second of a radioactive substance subjected to a vacuum is not affected.

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