Question

a) Tyndall effect is observed in colloids but not in solutions. Explain.
b) Give three examples of Tyndall effect observed around us.

Answer 1

a)

• Tyndall effect is the phenomenon in which the particles of a mixture scatter a beam of light passing through them.
• The particle size of a colloid ranges from 1-1000 nm and are big enough to scatter a beam of light passing through them.
• Therefore, Tyndall effect is observed in colloids.
• However, the particle size of a solution is less than 1 nm, and do not scatter a beam of light passing through them.
• Therefore, Tyndall effect is not observed in solutions.

b)

Three examples of Tyndall effect around us are:

• Scattering of sun rays passing through the canopy of dense forest.

• Scattering of light emitted from the headlight of a car in fog​.

• Scattering of light emitted from the lampposts on roads​.