Among the following, total number of radioactive elements are `ln, Ac, At, Ba, Tc, Pm, Ta, Xe

Answer

To determine the total number of radioactive elements from the given list (In, Ac, At, Ba, Tc, Pm, Ta, Xe), we will analyze each element one by one.

### Step-by-Step Solution:

1. **Identify the Elements**: The elements provided are:
- In (Indium)
- Ac (Actinium)
- At (Astatine)
- Ba (Barium)
- Tc (Technetium)
- Pm (Promethium)
- Ta (Tantalum)
- Xe (Xenon)

2. **Check Radioactivity**:
- **In (Indium)**: Indium is a stable element and not radioactive.
- **Ac (Actinium)**: Actinium is a radioactive element.
- **At (Astatine)**: Astatine is a radioactive element.
- **Ba (Barium)**: Barium is a stable element and not radioactive.
- **Tc (Technetium)**: Technetium is a radioactive element.
- **Pm (Promethium)**: Promethium is a radioactive element.
- **Ta (Tantalum)**: Tantalum is a stable element and not radioactive.
- **Xe (Xenon)**: Xenon is a stable element and not radioactive.

3. **Count the Radioactive Elements**:
- From the analysis:
- Radioactive elements: Ac, At, Tc, Pm
- Total radioactive elements = 4 (Ac, At, Tc, Pm)

### Final Answer:
The total number of radioactive elements among the given options is **4**.

---