Lung capacity

Lung capacity on PhotoPeach MATERIALS: - A tank - A tube - A bottle INSTRUCTIONS: - Fill the tank and the bottle with water. - Put the bottle upside down in the tank. - Put the tube in the bottle. - Fill your lungs with as much air as you can. - Blow through the tube. - Measure how many liters you have blown. WHY?: The air you blow through the tube expels the water in. The place were once there was water now there is air. You can measure the air you blow looking at the level of water in the bottle. WHAT DO YOU THINK ABOUT IT? WRITE YOUR COMMENTS.

Fatty foods

Fatty foods on PhotoPeach

MATERIALS:

Brown grocery paper, cut into small squares. Different foods to test: crisps, peanuts, apple, banana, butter, mayonnaise, oil, chocolate, cheese, nuts, popcorn, ham... INSTRUCTIONS:

- Rub each piece of food onto separate paper squares. Count to 20 while you rub, so that you test each food for the same amount of time.

- Label the squares so you remember which food you rubbed on each one.

- Put the papers in order from the most stained to the less.

- Leave them a week (an overnight is enough).

- After a week, put the papers in order again. You'll see that the order is different now.

WHY:

Fat stains the paper while other liquid substances (mostly water) evaporate.

WHAT DO YOU THINK ABOUT IT? WRITE YOUR COMMENTS.

International Year of Chemistry: a workshop.

Josep's mum, Núria , is a chemist. She came to school and did lots of experiments to us: a battery with a lemon, small pieces of paper that showed if a liquid was acid or basic, liquids that changed colour when adding some drops of another liquid... We thought they were magic!

When she finished we asked her many questions.

WHAT DO YOU THINK ABOUT IT? WRITE YOUR COMMENTS!

International Year of Chemistry: no fire for a fried egg

MATERIALS:

- An egg.

- A plate or a bowl.

- Alcohol.

INSTRUCTIONS:

- Break the egg and put it in the plate.

- Pour some alcohol on it.

- Wait half an hour.

- It's a fried egg!

WHY?

Eggs contain proteins. When you heat proteins they undergo a structural change called denaturation. You can get the same result with alcohol. In this process the egg white becomes solid and white.

WHAT DO YOU THINK ABOUT IT? WRITE YOUR COMMENTS!

International Year of Chemistry: the balloon

MATERIALS:

- A bottle.

- A balloon.

- Vinegar.

- Sodium bicarbonate.

- A funnel.

INSTRUCTIONS:

- Fill half of the bottle with vinegar.

- Fill the balloon with sodium bicarbonate. Use the funnel.

- Adjust the balloon to the bottle.

- Pour the bicarbonate to the vinegar.

- The balloon starts to blow up.

WHY?

When bicarbonate mixes with vinegar (an acid) it produces carbon dioxide. This is the gas that blows the balloon up.

WHAT DO YOU THIN ABOUT IT? WRITE YOUR COMMENTS!

International Year of Chemistry: Physical or Chemical change?

MATERIALS:

- 2 plates - 2 sheets of paper - a lighter INSTRUCTIONS: - Make a ball with one of the sheets and place it on a plate. - Fold the second sheet of paper, place it on the plate and burn it. - The first sheet has suffered a physical change, and the second one a chemical change. WHY? The first sheet of paper is still paper, it keeps its properties. It has only changed its shape and size: it's a physical change. The second sheet of paper isn't paper any more. Now it's something different, it's ash: it's a chemical change. WHAT DO YOU THINK ABUOT IT? WRITE YOUR COMMENTS!

Building bridges

MATERIALS:

4 thick books

1 piece of cardboard

paper clips

rubbers

INSTRUCTIONS:

Put the books in two piles about 15 cm apart.

Lay the piece of the cardboard on the books.

Put paper clips on the cardboard. Count them. The "bridge" starts to sag. Finally the bridge collapses.

Now make another bridge, but bend the piece of cardboard into an arch between the books.

Put paper clips and rubbers until it collapses.

This bridge is stronger than the first one.

WHY?

The first bridge collapses before because it is flat and it has to take all the weight.

In the second bridge the weight goes to the sides and it is shared by the books, so the card can support more weight.

WHAT DO YOU THINK ABOUT IT? WRITE YOUR COMMENTS.

Jumping egg

MATERIALS:

Two glasses

Two eggs

Vinegar

Water

INSTRUCTIONS:

- Fill a glass with water and put one egg into it.

- Fill the second glass with vinegar and put another egg in.

- Wait three or four days.

- The egg in vinegar hasn't got a shell. It's bigger and darker than the egg in water.

WHY:

Vinegar is an acid and dissolves the calcium in the eggshell. It is calcium that makes the shell hard. A thin flexible membrane just under the shell still holds the egg's shape.

Water does nothing to the eggshell.

Discopaper

Materials: - A bowl - An elastic band - Plastic film - Toilet paper - A radio Instructions: Stretch a piece of plastic film across the top of the bowl. Lay tiny pieces of toilet paper on. Place the bowl next to the radio. Turn on the radio. Turn up the volume. The toilet paper starts to move. Why: The sound from the radio makes air vibrate. If the music is very loud, vibrations are stronger. Vibrations make the plastic film vibrate, so the tiny pieces of toilet paper move too. Different styles of music have different speeds of vibration.

Paper chromatography

MATERIALS Paper towel Red, yellow and blue food colouring 1 glass Spoon Water Scissors An eye-dropper Water INSTRUCTIONS Drop one drop of red, one drop of yellow, and one drop of blue food colouring together on a glass. Mix the three drops together and observe the mixture. Cut a 3 cm strip of paper towel. Using the eye-dropper put a small drop of the food colour mixture in the centre of the paper towel strip about 3 cm from one end. Fill the other glass with water. Place the end of the paper towel strip with the food colouring dot into the water. Make sure the water does not touch the food colouring. Observe for 5-10 minutes. The water separates the food colouring mixture with separate portions of red, blue and yellow on the paper towel strip. WHY? Because the water creeps along the surface of the paper and dissolves the particles of colour. The components of the mixture move along the paper. The different colours do not move at the same speed because they all have different attractions to solvent and paper. WHAT DO YOU THINK ABOUT IT? WRITE YOUR OPINIONS!