The rate at which a solid , liquid or gaseous object spreads spontaneously across a space at any given time is called the diffusion rate of that object. The rate of diffusion of an object depends on its mass and intermolecular attraction ball. The lower the intermolecular attraction, the higher the diffusion rate, and the higher the intermolecular force of attraction, the lower the diffusion rate. As the temperature increases, the rate of diffusion increases as the inter-particle attraction force of the object decreases.