The isoelectric point is the $pH$ at which:

Tyndall effect is more pronounced in

The conditions given below are in the context of observing Tyndall effect in colloidal solutions:
$A$. The diameter of the colloidal particles is comparable to the wavelength of light used.
$B$. The diameter of the colloidal particles is much smaller than the wavelength of light used.
$C$. The diameter of the colloidal particles is much larger than the wavelength of light used.
$D$. The refractive indices of the dispersed phase and the dispersion medium are comparable.
$E$. The dispersed phase has a very different refractive index from the dispersion medium.
Choose the most appropriate conditions from the options given below:

When the dispersed phase is liquid and the dispersion medium is gas,then the colloidal system is called:

$100 \; mL$ of $5 \% \; (w/v)$ solution of $NaCl$ in water was prepared in a $250 \; mL$ beaker. Albumin from the egg was poured into the $NaCl$ solution and stirred well. This resulted in a/an:

Which metal sol cannot be prepared by Bredig's arc method?