High concentration of gelatin in water on heating gives a colloidal solution,which is called

Gold number is a measure of the

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.

Jelly is a form of

Which of the following electrolytes is least effective in causing flocculation of ferric hydroxide sol?

Why do painters add oil to paint when painting a wall with oil paint?