Define the terms : Galvanized iron and passive iron.

Explanation

### Step-by-Step Solution:

1. **Definition of Galvanized Iron**:
- Galvanized iron refers to iron that has been coated with a thin layer of zinc. This process is done to prevent the iron from corroding when exposed to moisture and air. The zinc layer acts as a protective barrier, which means that if the iron is exposed to corrosive elements, the zinc will corrode first, thereby protecting the underlying iron from rusting.

2. **Definition of Passive Iron**:
- Passive iron is iron that has been treated with nitric acid (HNO3). This treatment results in the formation of a protective oxide film on the surface of the iron. This oxide layer makes the iron inactive to air, preventing oxidation and corrosion. As a result, passive iron is less prone to rusting compared to untreated iron.

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