Consider the following statements regarding the properties of a colloid:

1. It is a heterogeneous mixture and is unstable.

2. The size of particles of a colloid is large and can be seen by naked eyes.

3. particles of a colloid are big enough to scatter a beam of light passing through it and make its path visible.

4. Fog, clouds, mist, and coloured gemstone are some of the examples of colloid.

Which of the statements given above is/are correct?