Question

Which of the following is not a mixture?

• A. Milk and chocolate
• B. Sulfur
• C. Air
• D. Brass

Answer 1

The correct option is B

Sulfur

Explanation for correct option:

B. Sulfur

Mixture:

• “A mixture contains more than one substance (element and/or compound) mixed in any proportion.”
• A mixture has a variable composition.
• Examples of mixtures are Mud, Air, Smog as well as Seawater.

Elements:

• “An element is a basic form of matter that cannot be broken down into simpler substances by chemical reactions.”
• Elements can be metals/non-metals/metalloids.
• Examples of elements are Iron $\left(\mathrm{Fe}\right)$ as well as Sulfur$\left(\mathrm{S}\right)$.

Thus, Sulfur is an element and not a mixture.

Explanation for incorrect options:

A. Milk and chocolate are a mixture.

C. Air is a mixture of various gases.

D. Brass is a mixture that is made up of copper and zinc with $66\%$ Copper and $34\%$ Zinc.

Hence. the correct option is B i.e. Sulfur is not a mixture.