Invisible Ink

What you’ll need:

• half a lemon
• bowl
• cotton bud
• white paper
• lamp or other light bulb

1. Squeeze the lemon juice into the bowl and add a few drops of water.
2. Mix with a spoon.
3. Dip the cotton bud into the mixture and use it to write a message onto the white paper.
4. Wait for the juice to dry so it becomes completely invisible.
5. When you are ready to read your secret message or show it to someone else, heat the paper by holding it close to a light bulb. 

Fun Fact

Lemon juice is an organic substance that turns brown when heated.

Dancing Food Colouring

What you’ll need:

• milk
• plate
• food colouring,three different colours
• dishwashing liquid
• cotton bud

1. Pour enough milk onto a plate to completely cover the bottom and to a depth of about 1cm.
2. Add drops of food colouring to the milk keeping them close together between the centre and the edge of the plate.
3. Place a drop of dishwashing liquid on the end of the cotton bud.
4. Push the soapy end of the cotton bud down in the middle of the plate and hold it there for 10 to 15 seconds.
5. Try to place the cotton bud in different places on the plate and see the food colouring continue to move even when the cotton bud is removed. 

Fun Fact

Milk contains tiny droplets of fat, which when combined with the bipolar characteristics of dishwashing
liquid causes the molecules to bend, roll and twist as the soap molecules scurry to join up with other fat molecules. This is what you see in the food colouring

Blowing up Balloons with CO2

What you’ll need:

• balloon
• 40ml water
• soft drink bottle
• 1 tsp baking soda
• drinking straw
• juice 1 lemon

1. Stretch the balloon to make it as easy as possible to inflate.
2. Pour the water into the soft drink bottle.
3. Add the teaspoon of baking soda and stir it with the straw until it has dissolved.
4. Pour the lemon juice in and quickly put the stretched balloon over the mouth of the bottle.

Fun Fact

When baking soda and lemon juice combine, they create carbon dioxide (CO2). The gas rises up and escapes
through the mouth of the bottle, which inflates the balloon.

The Leakproof Bag

What you’ll need:

• zipper storage bag
• water
• pencil

1. Ensure that your pencil is sharpenedto a point.
2. Fill a zipper bag between a half and three quarters full of water.
3. Hold the pencil in one hand and the top of the bag in your other hand.
4. Slowly, but firmly, push the pencil all the way through one side of the bag.
5. Then push the pencil through the other side of the bag. No water leaks! 

Fun Fact

Zipper bag plastic is made out of polymers. When you puncture the bag with the sharpened pencil you are separating polymer chains without breaking them.
The chain therefore squeezes tightly around the surface of the pencil preventing leaks.     

With acknowledgement to SPAR Savour Magazine.