Which of the following represent characteristics of a pure substance?
I. It has a uniform texture throughout (homogeneous).
(ii)It has a fixed boiling point or melting point.
III. It is made up of different kinds of atoms/molecules.
IV. It can be an element or a compound,

Options

A. II and III only
B. I and III only
C. I, II and IV only
D. III and IV only

Explanation

To determine the characteristics of a pure substance, let's analyze each statement provided in the question:

1. **Statement I: It has a uniform texture throughout (homogeneous).**
- A pure substance indeed has a uniform composition and texture throughout. This means that no matter where you take a sample from, it will look and behave the same. This statement is **true**.

2. **Statement II: It has a fixed boiling point or melting point.**
- Pure substances have specific boiling and melting points that do not change. For example, pure water boils at 100°C at standard atmospheric pressure. This statement is also **true**.

3. **Statement III: It is made up of different kinds of atoms/molecules.**
- A pure substance consists of only one type of atom or molecule. If it contains different kinds of atoms or molecules, it is considered a mixture, not a pure substance. Therefore, this statement is **false**.

4. **Statement IV: It can be an element or a compound.**
- Pure substances can be classified as either elements (like oxygen or gold) or compounds (like water or carbon dioxide). This statement is **true**.

Now, let's summarize the characteristics of a pure substance based on our analysis:

- **True Statements**: I, II, and IV
- **False Statement**: III

Thus, the characteristics of a pure substance are represented by statements I, II, and IV.

### Final Answer:
The characteristics of a pure substance are:
- I. It has a uniform texture throughout (homogeneous).
- II. It has a fixed boiling point or melting point.
- IV. It can be an element or a compound.

The correct answer is option **III** (which includes statements I, II, and IV).

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