Name two radioactive elements which are not found in observable quantities. Why is it too?

Explanation

To answer the question, we need to identify two radioactive elements that are not found in observable quantities and explain why this is the case.

### Step-by-Step Solution:

1. **Understanding Radioactive Elements**:
- Radioactive elements are those that undergo radioactive decay, releasing particles and energy. They have a characteristic property known as half-life, which is the time taken for half of the radioactive atoms in a sample to decay.

2. **Identifying Elements with Short Half-Lives**:
...