What is Diffusion?

Ever wondered why you can smell someone's perfume from across the room? That's diffusion in action! Diffusion is the net movement of particles from an area of high concentration to an area of low concentration, following what we call the concentration gradient.

Think of it like this: particles are naturally restless and want to spread out evenly. When perfume is sprayed in one corner of a room, those perfume particles don't stay put - they gradually move and spread throughout the entire space until they're evenly distributed.

The brilliant thing about diffusion is that no energy is required - it happens automatically. The total number of particles stays exactly the same; they just rearrange themselves from being crowded together to being more spread out.

Key terms you need to know:

• High concentration: loads of particles crammed into a small area
• Low concentration: fewer particles spread over the same area
• Concentration gradient: the "slope" particles follow as they move from crowded areas to less crowded ones

💡 Remember: Particles only move against the concentration gradient during active transport, which requires energy - but that's a topic for another day!