Which of the given statements is correct regarding properties of suspension?

I. Suspension is a heterogeneous mixture.
II. The particles of a suspension can be seen by the naked eye.

Both I and II

The correct answer is option 3. Both I and II.

Let us explain each statement:

I. Suspension is a heterogeneous mixture.

This statement is correct. A suspension is a type of mixture in which fine particles are dispersed in a fluid medium but are not dissolved. The particles are typically larger than those found in solutions and colloids. Because the particles are not dissolved, they do not uniformly distribute throughout the medium, resulting in a heterogeneous mixture. This means that the composition and properties of the mixture are not uniform throughout; instead, they vary from one region to another.

II. The particles of a suspension can be seen by the naked eye.

This statement is also correct. Unlike the particles in solutions, which are molecular or ionic and too small to be seen with the naked eye, the particles in a suspension are large enough to be visible. They may appear as cloudy or opaque regions within the fluid medium. Due to their size, they can scatter light, making the suspension appear cloudy or turbid. Thus, the presence of visible particles distinguishes suspensions from solutions, where particles are not visible.

In summary, both statements are correct: suspensions are indeed heterogeneous mixtures, and the particles in suspensions are visible to the naked eye. Therefore, the correct option is "3. Both I and II."