Choose the correct options, and explain the reason for the correct and incorrect options. Which among the following mixtures show the Tyndall Effect?

A mixture of:

(I) Air and dust particles

(II) Copper sulfate and water

(III) Starch and water

(IV) Acetone and water

Options:

(a) (I) and (II)       (b) (II) and (IV)

(c) (I) and (III)       (d) (III) and (IV)

(c) (I) and (III)

Explanation: The Tyndall effect is the scattering of light by particles in a mixture. It is shown by colloids and suspensions because their particles are large enough to scatter light. Air with dust particles shows the Tyndall effect because dust particles remain suspended in air and scatter light. Starch in water also shows the Tyndall effect because it forms a colloidal solution. However, copper sulfate in water and acetone in water form true solutions, whose particles are too small to scatter light.