Diffusion

Diffusion is the __________ out of a gas or liquid as their __________ move and mix.

• Diffusion only takes place if there is a __________ in concentration of the substance. This is known as the concentration __________.
• The substance moves from __________ concentration to area of __________ concentration.
• The higher the concentration gradient the __________ the rate of diffusion.
• Small molecules diffuse more __________ than large ones.