This document provides instructions for 4 science experiments involving kitchen materials: 1) Creating a "rainbow" out of paper towel that demonstrates capillary action by absorbing water through small holes. 2) Making a "lava lamp" by layering oil, vinegar, and baking soda that produces bubbles as the vinegar reacts with the baking soda. 3) Using lemon juice and heat to make invisible writing appear on paper due to the carbon in lemon juice browning when heated. 4) Growing crystals on string between two jars of hot water and baking soda that cool to form a super-saturated solution and deposit crystals.

1. St Peter’s School
Science Experiment 1
Please ask an adult for help and support.
You will need:
• Kitchen roll/paper towel
• Felt tip pens
• 2 x small bowls of water
• Paper clip
• Thread
1. Cut your kitchen roll into the shape of a rainbow.
2. Colour a rainbow with felt tips about 2cm up on both sides.
3. Attach your paper clip to the top and tie a piece of thread to it. This will give
you something to hold your rainbow with.
4. Fill each small container with water.
5. Hold your rainbow with the ends slightly submerged in the water then watch
your rainbow grow!
THE SCIENCE
This is called a capillary action! Water molecules like to stick to things—including
themselves. The fibres in the kitchen roll have lots of little holes. The water is
sucked through the holes and the next water molecule follows.

2. St Peter’s School
Science Experiment 2
Please ask an adult for help and support.
You will need:
• Vegetable/sunflower oil
• Vinegar
• Food colouring
• Bicarbonate of soda
• A plastic bottle
1. Add 3 spoons of bicarbonate of soda into the bottle.
2. Fill 2/3 of the container with the oil.
3. In a small cup, add some vinegar and several drops of food colouring.
4. Slowly add drops of your coloured vinegar into your oil/bicarb mixture and
watch your lava lamp come to life.
THE SCIENCE
Oil and vinegar do not have the same density (how heavy something is for its size).
Vinegar is more dense than oil—that’s why it sinks to the bottom.
Vinegar reacts with the bicarbonate of soda at the bottom of the container. The
chemical reaction creates bubbles of carbon dioxide which rise back to the top.

3. St Peter’s School
Science Experiment 3
Please ask an adult for help and support.
You will need:
• Lemon juice
• Cotton bud or paint brush
• Cup
• Paper
• Candle
1. Add 1 tablespoon of lemon juice to a cup. Freshly squeezed or bottled will
work the same.
2. Soak the cotton bud or paint brush in the lemon juice.
3. Write your message on the paper and leave to dry.
4. CAREFULLY, with an adult, slowly heat up the paper with a candle or with a heat
source.
5. Watch your message appear.
THE SCIENCE
Lemon juice contains carbon and when heated it discolours before the paper. At
room temperature it is the same colour as the paper. When carbon touches oxygen
(air) it goes brown.

4. St Peter’s School
Science Experiment 4
Please ask an adult for help and support.
You will need:
• 2 x glass jars
• Hot water
• Bicarbonate of Soda
• 2 x paper clips
• String or wool
• Small plate
1. Pour hot water into 2 jars and stir in bicarbonate of soda until no more will dis-
solve (about 6 teaspoons). When a layer forms at the bottom of the jar, this
means no more will dissolve.
2. Tie a paper clip to each end of the piece of wool or string and place each end in
each jar so it hangs between.
3. Put a small plate underneath the wool and jars.
4. Leave the jars for a week. Crystals will begin to form along the wool—hanging
down like stalactites.
THE SCIENCE
You've created a super-saturated solution. Hot water can hold more bicarb than
cold water. As the water cools the bicarb can no longer ‘fit’. As the water evapo-
rates, crystals form.