Which of the following statements are true for pure substances?
(i) Pure substances contain only one kind of particles.
(ii) Pure substances may be compounds or mixtures.
(iii) Pure substances have the same composition throughout.
(iv) Pure substance can be exemplified by all elements other than nickel.

Options

A. (i) and (ii)
B. (i) and (iii)
C. (iii) and (iv)
D. (ii) and (iii)

Explanation

To determine which of the statements about pure substances are true, let's analyze each statement step by step.

### Step-by-Step Solution:

1. **Statement (i): Pure substances contain only one kind of particles.**
- **Analysis:** A pure substance is defined as a material that has a uniform and definite composition. This means it contains only one type of particle, which could be atoms or molecules. Therefore, this statement is **true**.

2. **Statement (ii): Pure substances may be compounds or mixtures.**
- **Analysis:** Pure substances cannot be mixtures. A mixture contains two or more different types of particles and can be separated by physical means. Pure substances can be elements or compounds, but not mixtures. Therefore, this statement is **false**.

3. **Statement (iii): Pure substances have the same composition throughout.**
- **Analysis:** By definition, pure substances have a consistent composition throughout. This means that every sample of a pure substance will have the same properties and composition. Therefore, this statement is **true**.

4. **Statement (iv): Pure substances can be exemplified by all elements other than nickel.**
- **Analysis:** This statement is misleading. Pure substances can be exemplified by all elements, including nickel. A pure element contains only one type of particle (atoms of that element). Therefore, this statement is **false**.

### Final Conclusion:
- The true statements regarding pure substances are:
- (i) True
- (ii) False
- (iii) True
- (iv) False

Thus, the correct answers are statements (i) and (iii).