Explanation

The surface area of a spherical particle is proportional to the square of its diameter, and its volume is proportional to the cube of its diameter, so its specific surface (surface area volume) is inversely proportional to its diameter. With the decrease of particle diameter, the specific surface will increase significantly, and the surface atoms of particles will increase relatively, so that these surface atoms have high activity and are extremely unstable, resulting in particles showing different characteristics, which is called surface effect.

Classification