Plan
- What supplies do you need for this activity?
- You will need to freeze your ice spheres in advance – who will be in charge of doing that?
- Where will you do this experiment? If you do it inside, how will you make sure that the melting ice does not make a mess?
- What do you think will happen when you pour salt and water over the ice sphere?
Do
- Fill balloons with water – they do not need to be overly full. Water balloons work well for this activity.
- Freeze your balloons – you can put them in the freezer or just leave them outside overnight.
- Peel the balloon off of your frozen sphere.
- Place your sphere on the ground (if you’re outside) or a plate (if you’re inside).
- Sprinkle some salt over the sphere, then use a spoon, eye dropper or syringe to add coloured water to the balloon.
- What happens?
- Keep adding salt and water – see what happens as you add different amounts of each.
Review
- What happened when you added salt and water to the ice sphere? Is that what you thought would happen?
- What happens when you add different colours of water?
- What happens if you try this experiment without salt?
Materials
- Frozen ice spheres (fill balloons with water and freeze them)
- Water + food colouring
- Table salt
- Spoon, syringe, eyedropper or other way to move water onto the sphere.
- Plate and towels for easy clean up (if you’re inside)
Keep it Simple
- Just add coloured water to your ice spheres and see what happens. You may need to leave the sphere for a couple of minutes before adding more water.
Take it Further
- Using salt to lower ice’s melting point is a key part of making ice cream. Try making your own!
