States of Matter - Chemistry

= The process of transforming a solid matter into liquid by means of applying heat is called melting. 

Effusion: The passage of gases from a high pressure zone to a low pressure zone through a very small opening is called effusion.

Diffusion: The tendency of solid, liquid or gas to spread spontaneously and uniformly in any medium is called diffusion. 

Difference between Diffusion and Effusion:

1. Diffusion is a spontaneous and slow process. 

Effusion occurs faster in high pressure.