There's an explosion of colour in this experiment and the chance to learn all about convection too!
What do I need:
- A couple of identical glasses
- Two different colours of food colouring
- Some card
- Somewhere where you can make a mess!
How do I do it?
STEP1 - Fill one of your glasses with hot water and colour it a 'warm' colour, red is best for this!
WARNING: Don't go too hot with the water as you'll almost certainly spill some!
STEP2 - Fill your other glass with cold water and colour this a 'cool' colour. Blue would be ideal but I only had green to hand so used that for the cold!
STEP3 - Place your piece of cardboard over the top of your cold water. You'll have to be quick for this next bit! With no hesitation flip the cold water glass upside down! The water will stay in! (You might want to give this a try before you add the food colouring!) Gently place this glass on top of the glass of hot water!
STEP4 - Another tricky bit, I'm afraid! Slowly ease the cardboard out from between the two glasses (you'll probably spill a drop or two!)
STEP5 - Watch in amazement as the hot water shoots right up and mixes with the cold!
What's going on?
As we heat the water up we give it more energy. This means that the molecules are moving around faster and that the water takes up more space! So the water expands when you heat it up and becomes less dense! As you'll know from our other experiments less dense things float on top of more dense things and so the hot water will shoot up and mix with the cold!
More Fun Please - Experiment like a real scientist!
- Now try the experiment again with the hot water in the top position and the cold in the bottom, what happens?
- Be careful not to go too hot with the water, you can see from the photos that I spilled a bunch!