Erupting chalk ice

THINGS YOU WILL NEED

• ¼ cup baking soda
•  ¼ cup cornflour
• ½ cup water
• Two bowls
• Food colouring or watercolour paint - enough to colour the mixture
• Ice-cube tray
• Freezer
• Concreted area
• Old clothing or waterproof apron for your child (this can get messy!)

HOW TO DO IT

Mix together baking soda, cornflour, and water. Split the mixture into two separate bowls.

Add a few drops of different-coloured food colouring or watercolour paint to each bowl. Pour each coloured mixture into separate ice-cube trays and freeze.

Once frozen, pop out the ice-cube colours into separate bowls. The ice can be used like chalk to draw on concrete, and will dry into a chalky texture. The different colours will look gorgeous as they melt and blend into each other.

Ask your child to separate out a couple of the ice cubes and, together, pour a little vinegar onto the ice to watch the bubbly reaction. Alternatively, pour a little vinegar onto your child's chalk art and watch the fizz.

TIPS

• Adult supervision is required to ensure vinegar is kept away from little mouths and eyes.
• Chalk ice drawings become more visible as they dry.

WHAT LEARNING IS OCCURRING?

• Sensory: Your child will feel the different texture of the chalk as it melts
• Basic science concepts: Cause and effect, chemical reaction, melting and freezing
• Creativity