What is the particle size in a colloidal solution?

1. Between 10^-4 cm to 10^-7 cm

2. Between 10^-5 cm to 10^-7 cm

3. Less than 10^-7 cm

4. More than 10^-3 cm

The correct option is B

Between 10^-5 cm to 10^-7 cm

Explanation for the correct option:
(B) Between 10^-5 cm to 10^-7 cm

• Colloidal particles are larger than simple molecules but small enough to remain suspended. Their range of diameters is between 1 and 1000 nm, i.e. from 10-5 cm to 10-7 cm or 10-7 to 10^-9 m
• Colloid: it is a heterogeneous mixture in which one substance is dispersed in another substance which is called a dispersion medium.
• Dispersion medium: The medium the colloidal particles are distributed in is called the medium of dispersion.
• Dispersed phase: The phase that is dispersed or present in colloidal particle shape is called the dispersed phase.
• Example: Starch represents the dispersed phase in a starch solution, while water is the dispersing medium.

Explanation for the incorrect options:
(A) Between 10^-4 cm to 10^-7 cm
(C) Less than 10^-7 cm
(D) more than 10^-3 cm

• As we know that the particle size of colloids ranges from 10^-5 cm to 10^-7cm. So the above options are not suitable for the colloids.

Hence, option (B) is correct.