In the radioactive decay
`{:(._(z)X^(A) rarr _(Z+1)Y^(A)rarr_(Z-1)Z^(A-4) rarr_(Z-1)Z^(A-4)),(" high energy" " low energy"):}` the sequence of the radiation emitted is :

Options

A. `alpha, beta,gamma`
B. `gamma, alpha,beta`
C. `beta,gamma, alpha`
D. `beta,alpha,gamma`

Answer

To solve the question regarding the sequence of radiation emitted during the radioactive decay process, we need to analyze the decay steps provided in the question. The decay sequence is represented as follows:

1. **Initial Nucleus**: \(_{Z}X^{A}\)
2. **First Decay**: \(_{Z+1}Y^{A}\)
3. **Second Decay**: \(_{Z-1}Z^{A-4}\)
4. **Final Decay**: \(_{Z-1}Z^{A-4}\)

### Step-by-Step Solution:

1. **Identify the First Decay**:
- The first decay shows an increase in the atomic number (Z) by 1, while the mass number (A) remains unchanged.
- This indicates a **beta decay**, where a neutron is converted into a proton, resulting in the emission of a beta particle (electron).

2. **Identify the Second Decay**:
- The second decay shows a decrease in the atomic number (Z) by 1 and a decrease in the mass number (A) by 4.
- This indicates an **alpha decay**, where the nucleus emits an alpha particle (which consists of 2 protons and 2 neutrons), leading to a reduction of 4 in mass number and 2 in atomic number.

3. **Identify the Third Decay**:
- The third decay shows no change in the atomic number (Z) and no change in the mass number (A).
- This indicates a **gamma decay**, which involves the emission of gamma radiation. Gamma decay typically occurs after other types of decay to release excess energy without changing the atomic or mass number.

4. **Summarize the Sequence**:
- Based on the analysis, the sequence of radiation emitted during the decay process is:
- **Beta decay** (first step)
- **Alpha decay** (second step)
- **Gamma decay** (third step)

### Final Answer:
The sequence of radiation emitted is: **Beta, Alpha, Gamma**.