Corrosion of a metal involves change in _______.

Options

A. chemical composition
B. only colour and shape
C. only density
D. malleability and ductility

Explanation

To answer the question "Corrosion of a metal involves change in _______," we can follow these steps:

### Step 1: Understand the concept of corrosion
Corrosion is a chemical process where metals react with environmental factors such as oxygen, moisture, and other chemicals, leading to deterioration.

**Hint:** Corrosion is not just a physical change; it involves a reaction with the environment.

### Step 2: Identify what changes during corrosion
During corrosion, the metal undergoes a transformation that affects its chemical structure. For example, when iron rusts, it reacts with oxygen and water to form iron oxide (Fe2O3), which is a different chemical compound than the original iron.

**Hint:** Think about what happens to the metal at a molecular level when it corrodes.

### Step 3: Evaluate the options given
The options provided include:
- A) Chemical composition
- B) Only color and shape
- C) Only density
- D) Malleability and ductility

Among these options, the most relevant change that occurs during corrosion is in the chemical composition of the metal.

**Hint:** Focus on the fundamental changes in the material rather than just physical properties like color or shape.

### Step 4: Conclude the answer
Based on the understanding that corrosion involves a chemical reaction that alters the metal's original composition, the correct answer is:

**Answer:** Corrosion of a metal involves change in **chemical composition**.

### Summary of the solution:
Corrosion is a chemical process that changes the chemical composition of metals, such as iron rusting into iron oxide.