Tyndall effect is a phenomenon of

The Tyndall effect is defined as the phenomenon of scattering of light by colloidal particles [1]. When a beam of light strikes fine particles suspended in a medium—such as smoke, dust, or water droplets—the path of the beam becomes visible because the light is reflected diffusely or scattered in various directions [1]. Colloidal particles are larger than the molecules in a true solution but small enough to remain suspended; their size is typically in the range of 1 to 1000 nanometers, which is in the vicinity of the wavelength of visible light. This size allows them to deflect and scatter visible light effectively, a property that distinguishes colloids from true solutions where no such scattering occurs. While dust particles in the air can act as colloidal particles to produce this effect, the scientific definition specifically identifies the scattering mechanism by colloidal-sized particles [1].

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 10: The Human Eye and the Colourful World > 10.6.1 Tyndall Effect > p. 169