3.1 Diffusion

Objective: State that the energy for diffusion comes from the kinetic energy of molecules and ions.

Diffusion is the net movement of particles from a region of high concentration to a region of low concentration. This movement occurs because particles are constantly in motion due to their kinetic energy.

The kinetic energy of particles is directly related to their temperature. Higher temperature means greater kinetic energy, and therefore faster movement. This increased movement leads to particles spreading out from areas where they are more crowded (high concentration) to areas where they are less crowded (low concentration).

Here's a simple analogy: Imagine a crowd of people in a small room. They will naturally spread out to a larger room because individuals are constantly moving and bumping into each other. This spreading out is analogous to diffusion.

Key Concepts

• Kinetic Energy: The energy of motion. All particles have kinetic energy and are constantly moving.
• Concentration Gradient: The difference in concentration of a substance between two areas. Diffusion occurs down a concentration gradient.
• Net Movement: The overall movement of particles in a particular direction.

Table: Relationship between Kinetic Energy and Diffusion

Kinetic Energy	Effect on Particle Movement	Effect on Diffusion Rate
High	Particles move faster and more randomly.	Faster diffusion rate.
Low	Particles move slower and less randomly.	Slower diffusion rate.

In summary, the movement of particles during diffusion is driven by their inherent kinetic energy. The greater the kinetic energy, the faster the particles move and the quicker the diffusion process.