Colloids around us

Why are lyophilic colloids used as protective colloids?

Which cell of retina enable us to see coloured objects around us ?

Which cells of the retina enable us to see coloured objects around us?

Colloidation is a colloidal solution of :

Give reasons for the following : (i) Peptazing agent is added to convert a precipitate into a colloidal solution. (ii) Colloidal gold is used for intramuscular injection. (iii) Cottrell's smoke precipitator is fitted at the mouth of a chimeny used in factories.

Colloidal gold and calcium are used in