What is a primary cell? Give an example.

Explanation

### Step-by-Step Solution:

**Step 1: Definition of Primary Cell**
A primary cell is defined as a type of electrochemical cell that is designed to be used once and cannot be recharged. This means that the chemical reactions that occur within the cell are irreversible, and once the reactants are consumed, the cell cannot be restored to its original state.

**Step 2: Characteristics of Primary Cells**
- **Non-rechargeable:** Primary cells cannot be recharged once they are depleted.
- **Irreversible Reactions:** The chemical reactions that take place in primary cells proceed in one direction only, meaning that the products formed cannot be converted back into the original reactants.
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