Substances whose solutions can readily diffuse through parchment membranes are

Tyndall effect is observed only when:
$(i)$ the diameter of the dispersed particles is not much smaller than the wavelength of the light used.
$(ii)$ the refractive indices of the dispersed phase and the dispersion medium differ greatly in magnitude.
$(iii)$ the size of the particles is generally between $10^{-11} \ m$ and $10^{-9} \ m$ in diameter.
$(iv)$ the dispersed phase and the dispersion medium can be seen separately in the system.

When a few drops of dilute $HCl$ are added to a freshly prepared precipitate of ferric hydroxide,a reddish-brown colloidal solution is obtained. This phenomenon is known as .......

What type of colloid is milk?

Tyndall effect is observed due to

For which $ \text{lyophilic} $ sol is the $ \text{Gold Number} $ the highest?