Year 7 · Science · Particles and states of matter · Lesson 3
Diffusion and gas pressure
Diffusion - particles spreading from high to low concentration - what speeds it up, and how particle collisions cause gas pressure.
17-minute video lesson
Teaching, worked examples and 20 practice questions solved step by step.
Watch free for a monthWhat your child will learn
- Define diffusion
- Explain factors affecting diffusion
- Explain gas pressure
- Explain why heating raises pressure
The method
- Particles doing?
- What changes?
- Collisions / spread?
- Result.
Key words: diffusion, concentration, gas pressure, collision, random motion, temperature.
Worked examples
The first three practice questions from the lesson, with every step.
Question 1
What is diffusion?
- Step 1: Spread
Answer: particles spreading out and mixing
Question 2
Diffusion goes from high to ... concentration?
- Step 1: Opposite
Answer: low
Question 3
Why do particles diffuse?
- Step 1: Random
Answer: they move randomly