Ice Cube Race
Word of the day: melt
“We're having a race. The racers are ice cubes, and the winner is whoever melts first.”
Grab
- 4 ice cubes
- 4 small plates
- salt
- a sock or mitten
- a sunny window or warm spot
Do
- Give each ice cube a home: one plain, one with salt sprinkled on, one wrapped in a sock, one in their hand (with a towel).
- Guess the winner and the loser.
- Check every couple of minutes while you do something else.
- Bonus: put a string on an ice cube, sprinkle salt, wait a minute, and lift the cube by the string.
The big moment
Lift the ice cube with a string.
Ask (guess first, then try)
- Which one melted first?
- Did the sock keep it warm or keep it cold?
What's going on (for you)
Ice melts when heat flows into it. A hand is warm, so it gives heat fast. Salt makes ice melt at a colder temperature, which is why roads get salted. The sock is a surprise: it slows heat from getting in, so the wrapped cube lasts longest. Coats work the same way: they hold in the heat you already have.
If they want more
Freeze a toy in a block of ice and let them rescue it with warm water, salt and a spoon.