Hot, warm and ice-cold
Heat makes particles move faster.
Three tumblers
Potassium permanganate grains are put in three tumblers: ice-cold water, water at room temperature, and hot water.
In which tumbler will the colour spread fastest?
What this lesson covers
The idea
The movement of particles increases when heat is provided, so particles move faster in hot water than in cold water and a dissolving substance spreads faster.
Three tumblers
Potassium permanganate grains are put in three tumblers: ice-cold water, water at room temperature, and hot water.
In which tumbler will the colour spread fastest?
- Hot water
- Room temperature water
- Ice-cold water
Three tumblers
Drop grains in all three tumblers. Wait, and compare. Watch the water particles below each tumbler.
Heat and movement
The movement of particles increases when heat is provided. Water particles move fastest in hot water, slower at room temperature, and slowest in ice-cold water. So the colour spreads fastest in hot water.
Hot water can burn. Use it only with an adult.
- Water | The colour spreads
- Hot | Fastest
- Room temperature | Less quickly
- Ice-cold | Slowest
Notes
The movement of particles increases when heat is provided: particles move faster in hot water than in cold water, so a dissolving substance spreads faster.
Check yourself
In which water do the particles move the slowest?
Why does the colour spread faster in hot water than in cold water?
What happens to the movement of particles when heat is provided?
- Water at room temperature. They move slower here than in hot water, but faster than in ice-cold water.
- Hot water. Particles move fastest in hot water.
- Ice-cold water — correct. Yes. Less heat, slower movement.
- The water particles move faster in hot water — correct. Yes. They hit the colour particles more vigorously and spread them faster.
- Heat makes the colour particles bigger. Heat does not make particles bigger. It makes them move faster.
- Hot water has no attraction between its particles. Hot water is still a liquid. Its particles just move faster.
- It stops. Particles of liquids and gases are always moving, and heat makes them move faster.
- It increases — correct. Yes. Particles move faster.
- It decreases. Taking heat away slows particles down, not adding it.