Which term describes a mixture that scatters light and appears cloudy?

• A. Pure substance
• B. Heterogeneous mixture
• C. Colloid
• D. Homogeneous mixture

Answer: (C)

The main idea here is that light scattering combined with a cloudy, milky look points to a colloid. In a colloid, tiny particles are dispersed throughout another substance and stay suspended rather than dissolving away. Those particles are just large enough to scatter light, so you see a hazy or milky appearance—this is known as the Tyndall effect.

What that means in practice: a colloid has particles sized between molecules and bulk chunks, which keeps the mixture mixed for a long time without settling out quickly. Milk, fog, and certain emulsions are classic examples, showing the characteristic cloudy look.

If we think about the other options, a pure substance isn’t a mixture and wouldn’t inherently be cloudy. A homogeneous mixture is uniform throughout and typically appears clear. A heterogeneous mixture has visibly different parts and isn’t uniformly cloudy. A suspension can also scatter light and look cloudy, but its larger particles tend to settle over time, so it isn’t as stable a cloudy appearance as a colloid.

So, the term that describes a mixture that scatters light and looks cloudy is colloid.