The air takes up space- ballon in a bottle

The challenge is to blow a balloon inside a plastic bottle. A big bottle works better but you can use a small bottle if you want. But is it that easy? Lets see

What we need:

• plastic bottle and stopper,
• latex balloon,
• water,
• nail,
• hammer.

How to:

1. Place the balloon inside the bottle, with the tip out;
2. Try to inflate the balloon, try again!;
3. Remove the balloon;
4. Fill the bottle with water and cap it tight;
5. With the nail punch a hole in the bottle bottom; 
6. Remove the nail and uncap the bottle, what happens?,
7. Leave only a small amount of water in the bottle;
8. Place the balloon inside the bottle again, just like in step 1;
9. Try to inflate the balloon, what happens?;
10. When the balloon is full of air, use your finger to close the nail hole;
11. Stop blow, what happens?;
12. Now remove your finger, what happens?

What happens?
In step 2, you aren't able to inflate the balloon.
When you remove the nail and uncap the bottle- step 6- the water exits the bottle through the hole.
Step 9-  you are successful.
While your finger is in the hole the balloon will remain full of air- Step 11.
If you remove the finger the balloon deflates.

Why?   
Step2- The bottle is full of air, there is no room for anymore air.
when you punch the hole in the bottle the air can escape through it and and "make some space" to the air in the balloon , while you inflate the balloon it "pushes" the air and the water inside the bottle to the outside through the hole.
Same reason explains why the balloon remains inflated in step 11 and deflates in step 12, amazing humm?



Et Voilá!
It takes space

Enjoy!

Floating pin

Another demonstration. So simple but so interesting

What we need:

• straight pins,
• water,
• toilet paper,
• bowl.

How to:

1. Fill the bowl with water;
2. Wait a few seconds until the water stop moving;
3. Can you place a straight pin floating in the water? Try it;
4. What happened?
5. Try a second pin.
6. Place the pin on the top of  a piece of toilet paper;
7. Place both things in the water, very carefully and gently
8. Wait a few seconds.

What happens?
The paper sinks, the straight pint floats.

Why? 

Surface tension, that's the answer.

When we place the pin in the water, without using the paper, it immediately sinks, its weight is too high for the area it occupies, ie is very dense.

The paper, by contrast have much area for the weight, in fact it doesn't sink, actually it soaks, in other words water molecules fill the paper pores in it's porous structure and fill the voids in the web cellulose paper. this way the paper becomes heavier and sinks.

Surface tension is responsible for what one might call "skin."

The water surface is formed by a barrier of water molecules. This barrier is what allows insects to land on water, the soap bubbles to exist, and the pin does not sink.


The first pin sinks because it doesn't start from a position of equilibrium and rest, unlike the second which is resting on the paper. The paper when sinks exerts sufficient force on the skin of the water to bend it but not to break it, and the pin floats.

Et voilá!
It's magic! No, it's science!

Enjoy!

Dancing raisins in soda

QUESTION:
Will the CO2 released from a water with gas bottle be strong enough to take to the surface 6 raisins?

What we need:

• transparent glass,
• water with gas, the strongest work best,
• 6 raisins

How to:

1. Chose a easy to clean zone near the sink;
2. Fill the glass with the carbonated water, use a medium glass, if its too large the gas will escape to fast;
3. Drop the raisins in the water;
4. Observe.

What happens?
The raisins will go up and down in the water for a while.
Why?
The CO2 gas in water begins to free itself when we first open the bottle. This CO2 travels vertically through the glass until it comes into contact with the air, at this poit the gas is released into the atmosphere.

When the bubbles of carbon dioxide meet the raisins those are immediately trapped in the grape rough skin imperfections, which will do the raisin “move up” to the top. When they arrive at the top CO2 bubbles are released in the air and the raisin falls down o meet another set of CO2 bubbles and go up again, and the cycle repeats itself. This will happen until there is not enough CO2 in the water to elevate the raisins.

Make this demonstration a true experiment:

• Use vinegar and baking soda. This mix will produce CO2. Do the raisins dance? Use plain vinegar with no additives
• Use other carbonated beverages.
• What drink is most effective?
• Try to use drinks with sugar and with no sugar. Do you notice any difference in the dance?
• Repeat the experiment using plain water and effervescent Alka-Seltzer® tablets.

Remember, record all your observations so you can quickly draw conclusions. Use a timer to tell time.

Et voilá!
Raisins dancing!

Enjoy! 

It's magic? No it's Science

With water, and a cardboard you can do a little magic with your restless.
This water is defying gravity.
Thats because the air in it can't escape to let in new air.

Et voilá!

It looks like magic, it sounds like magic, it tastes like magic, but it's science!

Enjoy!