Which one of the following is not represented by sols?

The zig-zag motion of colloidal particles is due to

How are colloids classified on the basis of
$(i)$ physical states of components
$(ii)$ nature of dispersed phase and
$(iii)$ interaction between dispersed phase and dispersion medium?

Curdling of milk is caused due to the formation of which of the following acids by the bacteria?

The coagulating power of an ion for a given colloid depends on which of the following?

Gold number is a measure of the