Title Image by Eloise Robbins, 2000
Science In Your Kitchen
20 experiments for you to try at home
Brought to you by the Leith Academy Science Department
Welcome
Lots of people think that science only happens in a laboratory. Not
true. Science is all around you and, whether you realise it or not, you’re doing
science every day. When you wonder why your shadow changes shape during the day
or you find out who can kick a football the furthest, you're doing science.
This book contains details of 20 simple experiments you can do at home. None of
them need special equipment; you'll either have the things already or you can easily
get them at local shops.
Most of the experiments are easy to set up, though for one or two you'll find a
second pair of hands useful. For some experiments, an adult must be present.
Being a good scientist
- Be prepared - make sure you've got everything you need before you start an experiment.
- Watch carefully. Doing an experiment may seem the fun bit, but a good scientist
will take the time to really look at what is happening. Each experiment has a space
for you to write down or draw what you see. Give as much detail as you can.
- Think. You may not know why something you see has happened, but you might be able
to come up with some ideas. The world's most famous scientists - like Isaac Newton
and Albert Einstein - weren’t the ones who did the experiments. They were the ones
who were able to explain what happened.
When you’ve done most or all of these experiments, we'd like to know what you think.
Please complete the form at the back of this book and hand it to any teacher in
the science department.
Enjoy your experiments.
Note for parents
The experiments in this book can all be done safely by children, but it would
be useful for an adult to be present. For one or two of the experiments this is
essential - these are marked in the book.
The equipment needed should all be readily available. There’s a list at the back
of any slightly more unusual things, and where you can get them.
There is a temptation simply to do the experiments and not think too much about
what’s happening. This can be fun, but it’s not true science. Please encourage your
child to observe carefully and to write notes about what they see. Discuss what
happens in the experiments and ask them if they can suggest reasons for what has
happened. At the back of the book you’ll find a short explanation of each experiment.
Many of the experiments suggest new ideas. “What if I try this instead?” “What if
we change the amount of this?” This is good science and you should encourage it.
However, please be sure any further experiments you child does are sensible and
safe.
We would very much welcome your comments on this book. At the back you’ll find a
form you can complete once your child has done most or all of the experiments. Please
ask your child to hand it in to any member of the science department.
IMPORTANT NOTE
The experiments in this book use standard household equipment and
chemicals. If the experiments are carried out properly, they are safe to do. We
have indicated where we believe adult assistance is appropriate.
As a result, we cannot accept any liability for damage or injury
caused when carrying out the experiments in this book.
1 Fizz it up
What you need
Some vinegar, some bicarbonate of soda and a small dish.
What to do
Put about a teaspoon of bicarbonate of soda on to a dry dish.
Carefully dribble on a little vinegar.
What did you see?
Can you explain it?
Other ideas
Make a mini-volcano with plasticene.
Put some bicarbonate of soda into the ‘crater’. Add a few drops of red food colouring,
then add the vinegar. Watch the lava flow.
2 Yo-yo raisins
What you need
A can or fresh bottle of fizzy lemonade or fizzy water, a few raisins and a
tall glass.
What to do
Pour the lemonade into the glass.
Drop in a few raisins and watch for minute or two.
What did you see?
Can you explain it?
Other ideas
Try other things instead of raisins
- peanuts or small pieces of chocolate.
If you can get jumbo-size raisins, try comparing them with normal-size raisins.
3 The balancing egg
What you need
An egg and some salt
What to do
Pour a small pile of salt onto a dry table.
Balance an egg - pointy end down - on the pile of salt.
Gently blow away the salt from the bottom of the egg.
What did you see?
Can you explain it?
Other ideas
Does it make any difference if you use
a hard-boiled egg?
4 Bottle breaker Adult needed
What you need
A small glass bottle with a strong screw lid and three plastic bags.
What to do
Fill the bottle right to the top with water. Screw the lid on tightly. Put the
bottle inside a plastic bag. Then put the bottle and bag inside another plastic
bag. Then put it all in a third plastic bag.
Put the whole thing into the freezer or the ice compartment of the fridge and leave
it overnight.
With an adult present, look inside the bag the next morning.
What did you see?
Can you explain it?
Other ideas
Try a plastic bottle - do you think you’ll get the same result?
5 Lifting ice
What you need
An ice cube, a piece of wet string and some salt.
What to do
Put the ice cube on a plate.
Lay the end of the wet string on top of the ice cube.
Sprinkle some salt on to the top of the ice cube.
Wait a minute, then try to lift up the ice cube.
What did you see?
Can you explain it?
6 Indoor fireworks Adult
needed
What you need
An iron nail, a file and a candle.
What to do
Ask an adult to file down a nail into iron powder. This will take a while, but
you don’t need much.
Light the candle, then gently sprinkle the iron powder into the flame.
What did you see?
Can you explain it?
7 Red flowers from white
What you need
A white carnation flower and some dark red food colouring.
What to do
Half-fill an old cup or glass with water. Add some food colouring to the water
to get a fairly dark red.
Use scissors to cut 1 cm from the end of the stem of the carnation.
Put the carnation into the coloured water and leave for a few days.
What did you see?
Can you explain it?
Use a sharp knife to cut the stem of another white carnation lengthways.
Put each half of the stem in different coloured water - try red and blue.
8 Chromatography
What you need
Some felt pens - dark colours usually work best.
Some strips of paper cut from coffee filter papers - about 1 cm wide and 10 cm long.
You could also try using strips cut from newspaper, but make sure they’re cut from
the edge so there is no print on them.
What to do
Put a 1 cm depth of water in a small glass. Mark a dot with a felt pen 2 cm
from the bottom of the strip of paper. Put the paper into the glass so the end of
the paper is in the water but the ink dot is above the water.
Fold the other end of the paper around a pencil so you can leave it hanging in the
water. You must make sure the ink dot doesn’t go in the water. Now wait for a few
minutes, then look at the strip of paper.
What did you see?
Can you explain it?
9 Scrambled eggs Adult needed
What you need
A hard-boiled egg and a raw egg, both in their shells. (If you boil an egg for
this experiment, make sure it boils for ten minutes and let it cool.)
What to do
Stand the raw egg on end in the middle of a large table, and then spin it.
Do the same with the hard-boiled egg.
What did you see?
Can you explain it?
Other ideas
Lie a Smartie on the table, then try
spinning it in the same way.
10 Liquid layers
What you need
Golden syrup, cooking oil, water and a plastic bottle with the top cut off.
(You could use an old glass instead.)
What to do
Slowly pour in some syrup so there is a 2 - 3 cm layer in the bottom of the
bottle. Let the syrup settle.
Now slowly pour in a 2 - 3 cm layer of cooking oil.
Lastly, pour in a 2 - 3 cm layer of water. Let everything settle.
What did you see?
Can you explain it?
Other ideas
Stir up the contents of the bottle with
a spoon, then wait a few minutes.
11 Living yeast
What you need
Dried yeast (not the ‘easy-blend’ sort), some sugar, a glass bottle, a bowl
and a balloon.
What to do
Add about a teaspoon of yeast and a teaspoon of sugar to the bottle. Pour in
some warm (not boiling) water and swirl the bottle around.
Fit a balloon over the neck of the bottle. Put the bottle into a bowl of hot water
to keep it warm, and wait. (It may take several hours.)
What did you see?
Can you explain it?
Other ideas
When the experiment has finished, try
to tie the balloon. How does it float compared to a normal balloon?
12 Cabbages, acids and alkalis
Adult needed
What you need
A small red cabbage (not pickled cabbage), strips of blotting paper or filter
paper, bicarbonate of soda, vinegar.
What to do
Tear the red cabbage into small shreds. Boil the shreds in a small pan of water
for five minutes. Remove the cabbage, making sure you keep the liquid.
Let the liquid cool, then soak the strips of paper in it. Let the strips dry.
Add drops of different liquids to the strips of paper - you can try vinegar, lemon
juice or soapy water. Stir a little bicarbonate of soda into water, and try that
as well.
What did you see?
Can you explain it?
13 Home-made plastic Adult
needed
What you need
Full-fat milk (don’t use skimmed or semi-skimmed) and some vinegar.
What to do
Warm about 250 ml of milk in a pan. When it is just starting to bubble, stir
in a little vinegar.
Keep stirring. The mixture should start to change within a few seconds.
Let the mixture cool, then rinse the contents of the pan under the cold tap.
What did you see?
Can you explain it?
14 Telephone for two Adult
needed
What you need
Two plastic cups - the type you get from drinks machines are OK but stronger
plastic will help. Best of all would be two empty golden syrup tins.
About ten metres of string or cotton.
What to do
Ask an adult to make a small hole in the bottom of each cup or tin.
Thread the end of a piece of string through the hole in one of the cups. Tie a knot
so the string doesn’t pull back. The knot should be on the inside of the cup. Attach
the other end of the string to the other cup in the same way.
Get a friend to hold one of the cups to his or her mouth. Walk away until the string
is tight and put the other cup to your ear. Ask your friend to speak quietly into
their cup.
What did you hear?
Can you explain it?
15 D-I-Y stalactites
What you need
Salt, two small bottles, large paper-clips, wool or string, and a small saucer.
What to do
Stir plenty of salt into a large glass of very hot water. Keep stirring. If
all the salt dissolves, add more. Allow to cool, then pour half into each glass
bottle.
Attach a paper-clip to each end of a piece of wool - about 40 cm long.
Put one end of the wool in one of the bottles, and the other end of the wool in
the other bottle. Make sure the ends of the wool are in the solution.
Now make sure that the bottom of the loop of wool between the bottles is hanging
below the level of the salt solution in the bottles.
Place a saucer under the bottom of the loop of wool. Leave for a week.
What did you see?
Can you explain it?
16 Blow-up bottle
What you need
A fairly fresh plastic bottle of fizzy drink. (A 2 litre size works best.)
What to do
The bottle needs to be about half to three-quarters full. If necessary, drink
some.
Put the top back on tightly.
Try squashing in the sides of the bottle.
Now give the bottle a good shake.
Try squashing in the sides of the bottle again.
What did you see?
Can you explain it?
17 Floating eggs
What you need
Two large glasses, two fresh eggs and some salt.
What to do
Fill both glasses with hot water.
Into one of the glasses, stir a large spoonful of salt until it dissolves.
Carefully put an egg in each glass.
(If you don’t see anything unusual happen, add extra salt to the salty water and
stir again.)
What did you see?
Can you explain it?
18 How plants drink Adult
needed
What you need
A stick of celery, a sharp knife, some food colouring, an old mug or glass.
What to do
Cut a piece of celery about 8 cm long. Make sure it has a clean cut at each
end.
Put a 2 cm depth of water in an old mug or glass, and add some drops of food colouring
until the mixture is fairly dark.
Place the celery into the coloured water so that one end of the celery in under
the surface. Now leave it for two or three hours.
Look at the end of the celery that was dipped in the water. Use a sharp knife to
cut up the celery lengthways. See if you can pull out some of the ‘tubes’.
What did you see?
Can you explain it?
19 Invisible ink Adult needed
What you need
Fresh lemon juice, white paper, a small paintbrush and a warm oven.
What to do
Use the paintbrush to draw a picture or write a message on the paper using the
lemon juice.
Let the piece of paper dry completely.
Put the piece of paper in a warm oven for a few minutes.
What did you see?
Can you explain it?
Other ideas
Try using milk instead of lemon juice.
20 Growing crystals Adult
needed
What you need
Salt (sea salt is best because it comes in larger crystals), cotton, super glue,
an empty jam jar and a lollipop stick.
What to do
Fill the jar with hot water. Add plenty of salt and stir it to help it dissolve
quickly. If all the salt completely dissolves and there are no salt crystals at
the bottom of the jar, add some more and stir again. Then put the jar of salt solution
on one side to cool.
Ask an adult to super-glue the largest salt crystal you can find onto one end of
a length of cotton. (This is called the seed crystal.)
Wind the other end of the cotton around the lollipop stick. Put the stick over the
top of the jar so that the seed crystal is about halfway in to the solution.
Leave the jar in a cool place for a few days. Then lift out the seed crystal to
see how it’s getting on. You can then put it back in the solution and leave it for
a few more days. Check again.
What did you see?
Can you explain it?
Equipment
You’ll probably have most of the things you need for the experiments already. You
might not be too sure about some of them - here are more details.
Bicarbonate of soda
You can get this in the baking section of any supermarket. Make sure you don’t
use baking powder instead - they’re not the same.
Coffee filter papers
You’ll usually find these next to the ‘real’ coffee - not instant coffee - in
the supermarket. You could use blotting paper instead, which you can get from a
stationer’s.
Dried yeast
You should be able to get this from the baking section of a supermarket. Don’t
try to use easy-blend yeast - it probably won’t work.
Food colouring
Again, the baking section of the supermarket. Be very careful with food colourings
- they can stain badly.
So why does it work?
This section gives a short explanation for each of the experiments.
Don’t read them until you’ve done the experiment and tried to come up with your
own explanation.
1 Fizz it up
Vinegar is an acid. It reacts with the bicarbonate of soda to produce bubbles
of carbon dioxide gas. This is the fizz that you see.
2 Yo-yo raisins
Raisins are slightly denser than the lemonade, so they sink. But when they are
at the bottom of the glass, bubbles of gas stick to them. This makes the (raisin
+ bubbles) less dense that the lemonade, so the raisin rises to the top. The bubbles
then burst, so the raisin sinks again.
3 The balancing egg
When you blow away the salt, a few grains remain right under the point of the
egg. These are enough to keep the egg balanced.
4 Bottle breaker
When water freezes, it expands (gets bigger). If the bottle is absolutely full
and the top is tight, the water can only get bigger by breaking the bottle.
5 Lifting ice
Adding salt to the ice lowers its melting point. This means that the ice at
the top of the ice cube melts, and the string sinks slightly into the ice. The water
then freezes again, trapping the string in the ice.
6 Indoor fireworks
Because the iron is now in a fine powder, it can burn easily in the candle flame.
As there are thousands of tiny iron grains, you get a fireworks display.
7 Red flowers from white
Flowers drink by drawing liquid up tubes to all parts of the plant, including
the petals. If the liquid is coloured, the petals pick up that colour.
8 Chromatography
As the water rises up the strips of paper, it carries the ink with it. Different
colours of ink move at different speeds, so if the ink is made of a mixture of colours,
they will be separated.
9 Scrambled eggs
When you try to spin the unboiled egg, the liquid contents slop around inside
the egg and stop it from spinning. With a hardboiled egg, there’s nothing to slop
around and so the egg will spin.
10 Liquid layers
Some liquids are denser than others. (A litre of water has a greater mass than
a litre of oil, so we say the water is denser). Less dense liquids will float on
top of denser liquids.
11 Living yeast
Yeast, even when dried, is a living fungus. When it’s ‘woken up’ by being mixed
with warm water, it will feed on any sugar that it finds. The yeast produces carbon
dioxide gas as a waste product - this is what blows up the balloon.
Carbon dioxide is denser than air. A balloon filled with carbon dioxide will sink
to the ground quickly.
12 Cabbages, acids and alkalis
Red cabbage contains a chemical called an indicator. Indicators change colour
if they are added to acids or alkalis. Red cabbage juice should turn red in acids
and green in alkalis.
13 Home-made plastic
When vinegar, which is an acid, is added to warm milk, it sets up a chemical
reaction. This re-arranges the particles in the milk. Instead of being free to move
and runny, they start to stick together and become lumpy. These lumps become your
plastic.
14 Telephone for two
When you speak into one of the cups, your voice makes the air in the cup vibrate.
This makes the bottom of the cup vibrate. This vibration is passed down the string
and makes the bottom of the other cup vibrate. This in turn makes the air in the
cup vibrate - this is what your partner’s ear detects.
15 D-I-Y stalactites
The water, which is full of dissolved salt, soaks into the wool and starts to
drip into the saucer. As it drips, the water evaporates, leaving behind the salt
in a small stalactite.
16 Blow-up bottle
Fizzy drinks contain a lot of gas dissolved in them. When you shake the bottle,
some of this gas is released. This ‘blows up’ the bottle and makes it hard to squeeze
in the sides.
17 Floating eggs
A fresh egg is slightly denser than water, so it sinks. But adding salt to water
makes the water denser than the egg. This makes the egg float.
18 How plants drink
Plants have narrow tubes called xylem. Water passes up these tubes to all parts
of the plant. Xylem tubes in celery are quite big, so you should be able to see
them. The tubes show up as coloured dots on the end of the celery.
19 Invisible ink
When you put the paper in the oven to dry, all the water (which makes up most
of the lemon juice) evaporates. The chemicals that remain combine with oxygen in
the air, and turn brown.
20 Growing crystals
The salt solution you make is called ‘saturated’ - it is holding as much salt
as it possibly can. As some of the water slowly evaporates, the water that’s left
can’t hold all the dissolved salt. This means some of the salt forms around the
seed crystal, making it grow larger. With time, patience and lots of salt, it’s
possible to grow really huge crystals.
What do you think?
When you’ve done most or all of the experiments in this book, please take
a few minutes to answer these questions. Ask a parent to answer the questions on
the next page. Then carefully cut out this page and hand to your science teacher.
1. What did you think about the experiments in this book? (Tick one box.)
o Best thing I’ve ever done
o Pretty good
o OK
o Rubbish
2. Were you able to find all the things you needed?
o All of them
o Most of them
o Some of them
o Hardly any
3. Which two experiments did you think were the best?
__________________________ __________________________
4. Which two experiments did you think were the worst?
__________________________ __________________________
5. Do you think the experiments helped you to learn anything about science?
o I learnt a lot about science
o I learnt something about science
o I didn’t learn much about science
6. Any other comments?
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What do you think? (Parents)
When your child has done most or all of the experiments in this book, please
take a few minutes to answer these questions. Ask your child to answer the questions
on the previous page and then hand the page to his or her science teacher.
1. Did your child enjoy carrying out these experiments? (Tick one box.)
o A great deal
o Reasonably
o Not at all
2. Did you get involved in helping your child with the experiments?
o Yes
o No
3. Did your child discuss what they were doing with you?
o Yes
o No
4. Do you think the experiments helped your child to learn anything about science?
o They learnt a lot about science
o They learnt something about science
o They didn’t learn much about science
5. Did you find the explanations of the experiments helpful?
o Yes
o No
7. Would you recommend the book to friends with a child about the same age as yours?
o Yes
o No
6. Any other comments?
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