This is a blog of the 4th grade class in la Farigola de Vallcarca School in Barcelona. This year we are doing “Aula de Ciències” in English.
In this blog we want to show you the experiments we do in our Science Lab. Science is fun!

dilluns, 26 de març de 2012

A telephone

- Two plastic glasses
- 6 - 8 m. of fishing line
- 2 clips
- a cutter

- Make a hole on the bottom of the plastic glasses.  
- Put one end of the fishing line into the hole.
- Make a knot to a clip. Do the same with the other end.
- Tighten the fishing line and talk to a friend.

The  sound travels better through a solid (fishing line) than the air.

Lung capacity

- A tank
- A tube
- A plastic bottle with capacity measures
- Water

- Fill the tank with water.
- Fill the bottle with water and put the tube in it.
- Put the bottle upside down in the tank.
- Fill your lungs and blow in the tube.
- Look at your lung capacity in the bottle.

You fill your lungs as much as you can and  when you blow through the tube, all this air goes into the bottle and expels the water in the bottle, it occupies its place.


The candle goes out

- A candle
- A plate
- A glass
- Matches or a lighter
- Water

- Place the candle on the plate.
- Pour some water into the plate.
- Light the candle.
- Put the glass upside down on the plate.
- Look at the flame and the water in the glass.

The flame goes out and the water level in the glass rises.

The candle flame heats the air in the glass, and this hot air expands. Some of this hot air escapes out from under the glass  (you can see some bubbles). When the flame goes out, the air in the glass cools and contracts. The cool air inside of the glass creates a vacuum due to the low pressure inside the glass and the high pressure outside of the glass. 


dilluns, 30 de gener de 2012

Liquid or solid?

Liquid or solid? on PhotoPeach

- Cornflour
- Water
- A bowl
- A spoon

- Put two glasses of cornflour into the bowl.
- Add a glass of water and four or five drops of food colouring.
- Mix everything.
- Make a ball in your hands. Is it a solid or a liquid?
- Hold it up in your hand. Is it a solid or a liquid?

The mixture is solid and liquid at the same time.
Cornflour is made of lots of long tiny particles (molecules) which don't dissolve in water but spread themselves out. When you make a ball in your hands the particles join together and it looks like a solid; but when you hold it up the particles slide over each other and it looks like a liquid.


dimarts, 10 de gener de 2012

Floating egg

- 1 egg
- A glass of water
- A spoon
- Salt

- Fill the glass with water.
- Put the egg into the glass.
- The egg sinks.
- Add two spoonfuls of salt.
- Stir.
- Add more salt until the egg starts to float.

Salt water is denser than tap water. When water becomes salty enough, the egg weights less than water, so the egg floats to the top.


Water filter

- A plastic water
- Two glasses
- A piece of cotton wool
- Sand
- Sawdust
- Small stones
- Bigger stones
- Dirty water

- Cut the bottom of the bottle.
- Turn it upside down and place the materials in this order: cotton wood, sand, sawdust, small stones and big stones.
- Place the bottle in a glass.
- Pour some dirty water.
- Water is cleaner when it comes out.


What temperature does water boil in Tibet?

We haven't been able to take photos of the experiment, but here you have a video about it:


- A jar with its lid
- Water
- A stove or microwaves
- A bag with ice
- A dishcloth
- A thermometer

- Fill the jar with water and heat it.
- Wait until water is boiling.
- Close it quickly.
- Put the bag of ice onto the lid to cool the air in the jar.
- Water starts boiling again.
- Open the jar and check the temperature.
- It's 80 degrees.

When we close the jar, the air on the top is very hot. When we cool it with ice, its volume diminishes and so does the pressure. This pressure is similar to the one in Tibet.


dilluns, 19 de desembre de 2011



Two glasses

Two eggs




- 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.


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.


diumenge, 16 d’octubre de 2011

Colour Splash

Colour Splash on PhotoPeach

- 3 glasses
- oil
- water
- food colouring
- a spoon

1)- Fill a glass with water.
- Add some drops of food colouring.
- Water and food colouring mix.
2) - Fill a second glass with oil.
- Add some drops of food colouring.
- Stir with the spoon.
- Food colouring stays a little ball. It doesn't mix.
3) - Fill a third glass with water and some oil (a thin layer).
- Add some drops of food colouring.
- The colouring food drops don't mix and they sit in the oil layer, like floating.

1) - Food colouring is mainly made of water, so it can mix with water.
2) - As food colouring is made of water, it can't mix with oil. It forms balls.
3) - Each drop of food colouring is coated with oil, so the drops float on the oil layer. When you break the oil "coat", they mix with water.


dimarts, 24 de maig de 2011

Atmospheric pressure

atmospheric pressure on PhotoPeach

MATERIALS: A can Cooking tongs A camping stove A bowl with cold water INSTRUCTIONS: - Put some water in the can (a tablespoon). - Place the can on the stove. - Heat the can to boil water. You can see the water vapor rising from the can. Wait one minute. - Hold the can with the tongs. - Take the can, turn it upside down very quicky and dip it into the water in the bowl, so the hole is covered by water. - The can crushes. - We did the same, but we placed it on the water with the open on the top: it happened nothing. WHY?: By boiling the water, the water changes states from a liquid to a gas (vapor). The water vapor expands and pushes the air out of the can into the atmosphere. When we turn the can upside down and place in the water, the water vapor cools, condenses, contracts and the pressure in the can decreases. Then the pressure from the outside of the can (atmospheric pressure) is higher, pushes the can and crushes it . When we do the experiment with the opening on the top, the air from the outside goes in the can and the pressure in and out the can is balanced.