Free taster
5 of 6 sections open
The Invisible Bombardment
📖 The Invisible Bombardment
Right now, trillions of air particles are smashing into your skin at around 500 m/s. You don't feel individual impacts because they're tiny, but together they create atmospheric pressure — about 100,000 Newtons pressing on every square metre of your body! Heat a gas and particles move faster, hitting container walls harder and more often. In a sealed container, pressure SKYROCKETS. That's why aerosol cans warn "Do not expose to heat" — they can literally explode!
Pressure Equation
p = F / A
Pressure (Pa) = Force (N) ÷ Area (m²)
The Particle Explanation of Gas Pressure
Gas pressure arises from the constant, random bombardment of container walls by gas particles:
Earn the mark scheme marks
🧠 Memory Aid
Celsius to Kelvin (Edexcel and Eduqas only): Add 273. Remember with: "Kelvin is Celsius + 273 — K is above 0, C starts at −273." Or simply: K = C + 273.
Gas pressure particle explanation — the 3-step answer:
- Particles move faster (higher kinetic energy)
- More frequent collisions with walls
- Greater force per collision → higher pressure
Absolute zero: −273°C. Think "−273 is the floor — you can't go lower." Like the lowest floor of a building. Everything above is a positive Kelvin value.
Now try it yourself
Quiz · Question 1 of 29
A sealed gas container is heated. What happens to the pressure of the gas inside?
Tap an answer to check it
This topic in real past papers
Every real exam question we've found on gas pressure & temperature, with a full worked answer.