​Watch the video on diffusion:

https://youtu.be/lxHMJaXOzP4

​Watch the video on diffusion:

https://youtu.be/lxHMJaXOzP4

​Definition

Diffusion is the net movement of particles from an area of higher concentration to an area of lower concentration.

The process of diffusion is a passive process. This means that it requires no energy.

Factors that affect the rate of diffusion:

• Temperature

• Concentration

• Surface area

• Distance

The rate of diffusion is greater at higher temperatures. This is because the particles have more kinetic energy so they move faster.

​

​Temperature

Diffusion happens more quickly when there is a steep concentration gradient (i.e. a big difference in concentration between two areas). ​

​Concentration

A large surface area to volume ratio increases the rate of diffusion. This is because the particles have a bigger area to diffuse across.​

​Surface area

​The shorter the distance, the quicker the rate of diffusion. This is because the particles have less distance to travel.

​Distance

​Diffusion in the body

The process of diffusion takes place in many places in the body. For example, oxygen and carbon dioxide diffuse in and out of the lungs and also certain molecules diffuse in and out of cells.