Question

Which of the following is a mixture?

Answer 1

D. Sand.

Sand is a mixture of small particles of rocks or minerals.

Answer 2

Answer: The correct answer is Option D.

Explanation:

Mixture is defined as the combination of two or more different pure substances where each pure substance retains its original chemical properties.

A pure substances is defined as the substance that is formed by the combination of only one type of atom or only one type of molecule. The atoms or molecules forming a pure substance loose their original chemical properties.

From the given options:

Option A: carbon dioxide

Carbon dioxide is the combination of carbon and oxygen atom. This compound contains the molecules of carbon dioxide only. Thus, it is a pure substance.

Option B: silicon

Silicon element is formed by the combination of silicon atoms only. Thus, it is a pure substance.

Option C: Silicon dioxide

Silicon dioxide is the combination of silicon and oxygen atom. This compound contains the molecules of silicon dioxide only. Thus, it is a pure substance.

Option D: Sand

Sand is the mixture of silicon dioxide (known as quartz) with some rocks and minerals. Every substance retains its own chemical properties. Thus, it is a mixture.

From the above information, the correct answer is option D.