The element which shows radioactivity is

Options

A. `Mg`
B. `Sr`
C. `Ba`
D. `Ra`

Answer

To determine which element among the given options shows radioactivity, we can follow these steps:

### Step 1: Understand Radioactivity
Radioactivity is the process by which unstable atomic nuclei lose energy by emitting radiation. This occurs in order to achieve a more stable form.

### Step 2: Identify the Options
We need to look at the options provided in the question to identify which one is known for its radioactive properties.

### Step 3: Analyze Each Option
Among the options, we need to check which elements are known to be radioactive. Common radioactive elements include uranium, thorium, and radon.

### Step 4: Confirm the Radioactive Element
Radon is a noble gas that is known to be radioactive. It undergoes radioactive decay to form more stable elements. Therefore, radon is the element that shows radioactivity.

### Step 5: Conclusion
Based on the analysis, the element that shows radioactivity is **Radon**.

### Final Answer
The element which shows radioactivity is **Radon**.

---