Colloid Properties: Identifying the Exception

Colloids are systems where particles are dispersed in another medium. Understanding their key properties is essential to identify statements that do not align with their nature.

Defining Characteristics of Colloids

• Colloids are heterogeneous mixtures.
• Their dispersed particles are typically between 1 nanometer (nm) and 1000 nm.
• Individual particles are generally invisible to the naked eye due to their small size.
• Colloidal particles remain suspended and do not settle out easily when left undisturbed, indicating system stability.
• Colloids exhibit the Tyndall effect, which is the scattering of a light beam as it passes through the colloid.

Evaluating the Options

• Option 2: "A colloid is a heterogeneous mixture." This is a correct statement defining colloids.
• Option 3: "They do not settle down when left undisturbed." This describes the stability characteristic of colloids.
• Option 4: "Due to too small size, individual particles cannot be seen with naked eyes." This accurately reflects the particle size range in colloids.
• Option 1: "Colloid cannot scatter a beam of light passing through it." This statement contradicts the Tyndall effect. Colloids are known to scatter light.

Identifying the Incorrect Property

Since colloids scatter light (Tyndall effect), the statement claiming they cannot scatter light is false. Therefore, this is the option that is NOT a property of colloids.