What kind of radioactive decay does not lead to the formation of a daughter nucleus that is an isobar of the parent nucleus

Options

A. `alpha-`rays
B. `beta-`rays
C. Positron
D. Electron capture

Explanation

To solve the question, "What kind of radioactive decay does not lead to the formation of a daughter nucleus that is an isobar of the parent nucleus?", we need to understand the types of radioactive decay and how they affect the mass and atomic number of the parent nucleus.

### Step-by-Step Solution:

1. **Understanding Isobars**:
- Isobars are nuclei that have the same mass number (total number of protons and neutrons) but different atomic numbers (number of protons). This means they are different elements.

2. **Types of Radioactive Decay**:
- There are several types of radioactive decay: alpha decay, beta decay, positron emission, and electron capture.

3. **Analyzing Alpha Decay**:
- In alpha decay, the parent nucleus emits an alpha particle (2 protons and 2 neutrons). This decreases the mass number by 4 and the atomic number by 2, resulting in a daughter nucleus that is not an isobar (it has a different mass number).

4. **Analyzing Beta Decay**:
- In beta decay, a neutron in the parent nucleus is converted into a proton, emitting a beta particle (an electron). The mass number remains the same, but the atomic number increases by 1. The daughter nucleus is an isobar (same mass number).

5. **Analyzing Positron Emission**:
- In positron emission, a proton is converted into a neutron, emitting a positron. The mass number remains the same, but the atomic number decreases by 1. The daughter nucleus is also an isobar.

6. **Analyzing Electron Capture**:
- In electron capture, an electron is captured by the nucleus, converting a proton into a neutron. The mass number remains the same, but the atomic number decreases by 1. The daughter nucleus is an isobar.

7. **Conclusion**:
- The only type of decay that does not lead to the formation of an isobar is **alpha decay**, as it changes both the mass number and the atomic number of the parent nucleus.

### Final Answer:
The kind of radioactive decay that does not lead to the formation of a daughter nucleus that is an isobar of the parent nucleus is **alpha decay**.

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