In a radioactive decay, a nucleus is transformed into another with the emission of a positron. In this process the neutron-proton ratio

Options

A. Decreases
B. Increases
C. Remains same
D. May decreases or increases

Answer

To solve the question regarding the change in the neutron-proton ratio during the emission of a positron in radioactive decay, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Positron Emission**:
- In positron emission, a proton in the nucleus is transformed into a neutron. This process can be represented as:
\[ p \rightarrow n + e^+ \]
- Here, \( p \) is a proton, \( n \) is a neutron, and \( e^+ \) is the emitted positron.

2. **Change in Proton and Neutron Count**:
- Before the decay, let’s denote the number of protons as \( Z \) and the number of neutrons as \( N \).
- After the positron emission, the new number of protons becomes \( Z - 1 \) (since one proton is converted into a neutron), and the number of neutrons becomes \( N + 1 \) (since one neutron is created).

3. **Calculating the Neutron-Proton Ratio**:
- The neutron-proton ratio before the decay is:
\[ \text{Initial Ratio} = \frac{N}{Z} \]
- After the decay, the new neutron-proton ratio becomes:
\[ \text{New Ratio} = \frac{N + 1}{Z - 1} \]

4. **Analyzing the Change in Ratio**:
- To determine whether the neutron-proton ratio increases or decreases, we need to compare the initial and new ratios:
\[ \text{New Ratio} = \frac{N + 1}{Z - 1} \]
- Since \( N \) increases by 1 and \( Z \) decreases by 1, the numerator increases while the denominator decreases.

5. **Conclusion**:
- As a result, the overall neutron-proton ratio increases. Therefore, the answer to the question is that the neutron-proton ratio **increases** during the emission of a positron.

### Final Answer:
The neutron-proton ratio **increases** during the emission of a positron.

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