Identify the soft metal among the following

Options

A. iron
B. aluminium
C. magnesium
D. potassium

Explanation

To identify the soft metal among the given options, we can follow these steps:

### Step-by-Step Solution:

1. **Understand What Metals Are**:
- Metals are naturally occurring elements that consist of only one type of atom. They are typically solid at room temperature and are known for their ability to conduct heat and electricity.

2. **Recognize the Properties of Metals**:
- Most metals are hard, but some metals are classified as soft. Soft metals can be easily deformed or cut.

3. **Identify Characteristics of Soft Metals**:
- Soft metals tend to have larger atomic sizes, which can reduce the attraction forces between the nucleus and the electrons. This weaker attraction results in a softer structure.

4. **Examples of Soft Metals**:
- Potassium and sodium are two well-known examples of soft metals. They are so soft that they can be cut with a knife.

5. **Select the Correct Option**:
- If the options provided include potassium or sodium, then either of these would be the correct answer as they are classified as soft metals.

### Conclusion:
- Based on the properties and examples discussed, the soft metal among the options is **potassium** or **sodium**.