List any two properties of a colloid.

Explanation:

(a) Properties of a colloid (any four)

(i) A colloid is a heterogeneous mixture.

(ii) The size of particles of a colloid is too small to be individually seen by naked eyes.

(iii) Colloids are big enough to scatter a beam of light passing through it and make its path visible.

(iv) They do not settle down when left undisturbed, that is, a colloid is quite stable.

(v) They cannot be separated from the mixture by the process of filtration. But, a special technique of separation known as centrifugation can be used to separate the colloidal particles.