An aerosol is a type of colloid in which.......

Comment on the statement that "colloid is not a substance but a state of substance".

Different colloidal particles of gold having different colours,obtained from different methods are due to:

The number of colloidal systems from the following,which will have 'liquid' as the dispersion medium,is $.........$.
Gem stones,paints,smoke,cheese,milk,hair cream,insecticide sprays,froth,soap lather.

Gold sol is not:

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$.
Assertion $(A)$: Dissolved substances can be removed from a colloidal solution by diffusion through a parchment paper.
Reason $(R)$: Particles in a true solution cannot pass through parchment paper but the colloidal particles can pass through the parchment paper.
In the light of the above statements,choose the correct answer from the options given below.