Which of the following statement is/are correct?

1. Colloids are heterogeneous.
2. Colloids cannot scatter the beam of light.
3. Colloidal particles are not visible to the naked eye.
4. Components of colloids can be separated by centrifugation.

The properties of colloids are as follows:

• A colloid is a heterogeneous mixture.
• The size of the particles of a colloid is too small to be individually seen by the naked eye.
• Colloids are big enough to scatter a beam of light passing through them and make their path visible.
• The components of the colloid can be separated by centrifugation.
• So the correct statements are 1,3 and 4.