Homemade glue

This is a non toxic, easy and inexpensive way to do child craft glue.

This needs adult supervision, remember that the kitchen can be a dangerous place to play in.

What we need:

• 1/2 cup hot water,
• 1 tablespoon vinegar,
• 2 tablespoons of milk powder ,
• 1/2 tablespoon of  baking soda,
• water,
• 1 coffee filter, 
• 1 funnel,
• a plastic/ glass containner,
• 1 tablespoon,
• plate.

How to:

1. Mix the hot water and the powder milk until dissolves;
2. Add the vinegar, the milk will form 2 distinct parts, the serum and the curds;
3. Keep mixing this mixture until curds and serum are well separated;
4. Place the filter in the funnel;
5. Place the funnel in the container;
6. Filter the previous mix;
7. If necessary raise a little bit the funnel so the air can flow, remember that air takes up space;
8. When the funnel is full "squeeze" the filter a bit, carefully;
9. Discard the serum;
10. In a small plate, using the spoon, break the serum layer into small pieces;
11. Add one hot water teaspoon and about 1/4 teaspoon baking soda;
12. Mix it all well until the adhesive becomes soft and more fluid;
13. If the mixture is too thick add a little more water, if it has lumps add more baking soda.
14. When not in use the adhesive covering it with transparent paper. 

With time the glue becomes more transparent and liquid. Trash the glue when it starts to smell slightly spoiled milk.

Note:
If the milk does not curdle try:

• add more vinegar;
• heat the mixture;
• use more hot water.

Et voilá!
you can almos eat it

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! 

The mysterious blast

Magic Science Tricks video.

TRICK Nº3. The mysterious blast


NOTE: This trick must heave adult supervision.

What we need:

• candles,
• matches,
• sodium bicarbonate, baking soda,
• vinegar, normal, without flavor,
• a glass container, with a large opening.

How to:

1. Light the candles;
2. Leave it burning for a while;
3. Pour the vinegar in container;
4. Add half a measure of bicarbonate;
5. Quickly put your hand over the cup, keep your hand there for a few seconds, until the bubbling calms down
6. Hold the container 1 in above the candle wick;
7. Tilt it as much as you can without the liquid content spill over the candles.

What happens?
The flame extinguish.

Why?
When we mix vinegar and baking soda a reaction happens, in this reaction water (liquid), carbon dioxide (gas) and sodium acetate (liquid) are formed. The bubbling is the result of this.
When we place our hand on the flask we don't prevent the gas to escape, we just slow it down, a small amount of it stay inside the container. When we tilt the container near the candles the CO2 escapes, and as result the O2 (oxygen) concentration drops, resulting in the extinction of the flame. This happens because one of the 3 necessary elements for a combustion is missing- the O2 -Check more information about this.

NOTE: CO2 molecule is heavier then O2 molecule.

That's why CO2 is a extinguishing agent, but like all extinguishing agents it can't be used indiscriminately:

Referências:
http://www.fiocruz.br/biosseguranca/Bis/lab_virtual/fogo.html 
http://www.fire-extinguisher101.com/agents.html

Et voilá!
It's Magic

Enjoy!

Vulcano- Sodium Bicarbonate and Vinager eruption

This is one of the most popular homemade experiences, not the one that give us less work but the one that has more fans with amazing results.
Don’t build your volcano indoors, chose a place where you can do a big and huge mess, with fresh air circulation, vinegar smell can become very strong.

We will need:

• baking soda- sodium bicarbonate,
• vinegar, white and without flavors will work better,
• food coloring, lava is red but you can do it any color you chose, 
• plastic bottle, PET, medium,
• 6 flour cups,
• 2 water cups,
• 4 oil tablespoons,
• 2 salt cups,
• tap water,
• dishwasher detergent,
• big bowl,
• materials like leaves, branches, sticks... ,
• large board.

How to

FASE1

1. Prepare the place where you are going to build the volcano, beware with your clothes;
2. Mix the flour, the water, the salt and the oil in the bowl;
3. Mix until homogenized;
4. Place the bottle on the board and mold the volcano cone around it. The bottleneck will be the crater and therefore must remain open;
5. With the materials you collect- leaves, branches, sticks... - place your trees, houses, bridges, etc.

FASE 2- Eruption

1. Fill the bottle in the volcano halfway with the tap water;
2. Add food coloring, and about 6 dishwasher detergent drop;
3. Add 3 or 4 tablespoons of baking soda;
4. Squeeze vinegar bottle to the crater;

NOTE: As soon as you squeeze the vintage the chemical reaction begins, but don’t stop, keep squeezing the bottle for a few more seconds.

What happened?
Vinegar (acetic acid) reacts with sodium bicarbonate and neutralizes it. In the reaction Carbon Dioxide (CO2) is formed and produces the bubbly and effervescent effect.
Food coloring gives color to your lava and the dishwasher detergent helps the effect to last longer.

Et voila!
Enjoy!

Invisible Ink, easy to write hard to read

Secret messages, they love it! To be able to write something on a piece of paper that no one can read is amazing.

Today we are going to see 3 ways to write something that no one can read but you, you will doubt about which the paper sheet was used.

Invisible ink with baking soda
We already used baking soda on several demonstrations and fun games, today we will use it to write…

We will need:

• 1 cup,
• 60ml of water,
• The same amount of sodium bicarbonate,
• toothpicks,
• paper. 

How to:

1. Measure 60ml of water;
2. Pour water into the cup;
3. Measure 60 ml of sodium bicarbonate, this is solid, so it may seem strange measure in ml, but do it :);
4. Mix baking soda in water;
5. Mix it until the solution is homogenized;
6. Get your paper, and write your message with the toothpick.

How do you read it? 
Spread grape juice over the sheet; use a sponge or a brush. 
NOTE: the grape juice leaves stain.

Why? 
Sodium bicarbonate is a chemical compound that has a basic pH, the grape juice is acid, and the reaction between the two rise to a third colour, visible to the naked eye.

Invisible ink with milk

We need:

• Milk,
• Toothpick,
• Paper sheet.

How to:

1. Put some milk in a bowl;
2. With the toothpick or brush to write the secret message;
3. Let dry completely.

How do you read it? 
There are several hypotheses; all of them require a heat source, and the supervision of an adult.
You can iron the sheet, place a cloth between the iron and the message so the iron dot get dirt, you can heat the sheet next to a lamp, be careful so it doesn’t get on fire, or, and finally, you can use the stove.

Why? 
Milk is an organic product, and burns at a slower speed than the paper. When you heat the paper, the milk is leaves a brownish colour and you can read the message in the white sheet.

Invisible ink with lemon:

We need:

• Lemon juice,
• Toothpick,
• Paper sheet.

How to:

1. Place a little lemon juice on a plate;
2. With the toothpick or brush write the secret message;
3. Let dry completely.

How do you read it? 
As in the the milk ink, you can pass the iron sheet, the sheet can heat with a lamp, or you can use the stove, either of these alternatives requires adult supervision. There is another way to see the message by putting salt on the sheet, in this case wait about 60sec and clean the salt, then, and carefully pass a crayon over it.

Why? 
For the same reason that points to the use of milk

In addition to these dyes, we can use other products such as white wine, vinegar, other fruit ...
You can make this demonstration in an experiment using other liquids that you think that might work.
Register which works best and what are the safest methods to read, do not forget that the aim is to get a top-secret message without being caught.

Et voila!
Nobody will notice that blank sheet on the table.

Enjoy!