Growing crystals at home

What is a crystal?
Crystals are regular structures formed by a regular repeating pattern of atoms or molecules.

These structures grow by a process called nucleation. During nucleation, the atoms or molecules of what we want to transform in a crystal (solute) are dissolved in a solvent. The particles of the solute will tend to cluster together, forming subunits of atoms or molecules. These larger particles will also group with each other and eventually become large enough to "pop out" the solution (crystallize).

Other solute molecules will continue to adhere to the surface of the crystal, causing it to grow until equilibrium is achieved between the solute molecules in the crystal and the solution.

Growing crystals
Three factors that can influence the growth of "home" crystals:

• A good/poor solution saturation- The first stage of home crystal growth is a saturated solute. In a saturated solution the probability of molecules colliding with each other in order to form a core for initiating nucleation is greatly increased.

• Surface type-A rough surface tends to be more attractive for nucleation. It is more likely that a crystal is formed on a piece of rough rope than the in the smooth walls of a glass.

• The presence of deposits in the bottom-This occurs when the solution is not scrambled or means that too much solute was added to saturate the solution. The presence of these deposits create areas for optimum crystal growth however prevents crystal formation in the "target."

Lets see how to grow sugar crystals, these crystals can be sucked and eaten like a lollipop. This demonstration may take up to 3 weeks.


We will need:

• 3 cups of sugar, we have to adjust this quantity, we want to saturated at 100% but no precipitate,
• cup of water, to boil,
• food coloring,
• small jar,
• small bowl,
• wood stick, or rope,
• kitchen paper or paper filter.

How to:

1. Boil the water, careful with burns!;
2. In the bowl, mix the boiling water with the sugar;
3. Stir the water until all the sugar is dissolved;
4. If you want to give sugar some color, now it's the time, add the food coloring;
5. Place this solution in the jar, attention! wash the jar really well to avoid nucleation in it's walls;
6. Avoid any amount of sugar precipitate in the jar- any not dissolved sugar-, this sugar will be a good nucleation "start point";
7. Suspend the stick or rope in the solution, do not wash those, we want this to be a suitable "start up" spot for nucleation;
8. Chose a nice and quiet spot to place your jar for at least 3 weeks;
9. Wait until the solution cool and cover it with a paper filter. 

What happens?  
After cooling the solution will use nucleation spots to form crystals.

NOTE: You must check the jar on daily basis, if you see any nucleation in jar walls, change the jar;

Wait about 3 weeks for excellent results.

Go further:

• Follow the growing crystals with a graph;
• Use salt and compare the growing velocity with the sugar;
• Use 3 jars, in the first one use boiling water, in the second tepid water, and in the last one repeat the essay with cold water;
• Try to dissolve the sugar/salt/other while the water is boiling;
• I am sure you can remember other ways to change this demonstration into a experiment...

 Source: about.com; squidoo.com; buzzle.com
Et Voilá!
Science you can eat!  

Enjoy!

Nature finds a way- light labyrinth

It's amazing how the sentence "Nature finds a way" is incredibly correct, everyone knows at least one story about animals saving people or about animals doing thousands of  km despite the unimaginable difficulties- like monarch butterflies or salmon going up the river.

Nature follows a small set of rules that allow ecosystems to function in equilibrium theoretically "ad eternum" if they are not disturbed by the "human hand".

Today I bring you a demonstration of how nature always finds a way to overcome the difficulties.
The test is very simple allows direct observation of the struggle for life.

We will need:

• potato;
• small plastic container/pot, like a cup,
• soil,
• shoe box,
• wooden blocks, legos®, or other small obstacles.

How to:

1. Allow the potatoes a few weeks at room temperature, so they can germinate, this procedure should be done in dry conditions, with light and warm. This procedure can take up to 6 weeks; 
2. Take the potatoes and place them in the container with the "little eyes" facing upwards;
3. Cover the potatoes with moist soil;
4. In the narrow side of the box make a round hole the size of a small coin;
5. Put the pot inside the box at the opposite end to the hole that opened in the box;
6. build small walls and obstacles using the legos®;
7. Place these obstacles inside the box, make sure that there is at least one free path to the hole, don't close the hole;
8. Close and seal the box, make sure no light can get in except from the hole;
9. Place the box somewhere with direct light with the hole facing the light source;
10. Wait 3 or 4 days and observe.

What happens?
After a while the potato will grow in light direction, sprouts will naturally go around obstacles in light direction

Why?Because the plant needs light to produce food, and thus growth will always be towards the light.
 
Go further: 
Repeat this with other plants.
"Do all plants grow in the same way?" 
you can use dry beans, onion.
 
Et Voilá!
Nature finds a way!

Enjoy!

Easter painting pages

Painting pages just for you.
Print and color.
All of this images were found on the internet.

Et voilá!
Have fun!

Enjoy!

Food coloring chromatography

QUESTION: Is it possible to separate the colors of a mixture of food colorings after they have been mixed?

What we need:

• coffee filters,
• wooden skewer,
• food coloring, yellow, green and blue,
• 4 glass containers,
• markers
• 4 paper clips,water.

How to:

• Prepare the work area, chose a easy to clean zone in outside or in the kitchen, food coloring usually leave messy stains;
• Identify the bottles, assign one or two letters each color, e.g. bottle Ye (yellow) Bl (blue) Gl (green) and Mix (mixed colors), or simply ABCD, write down in your notebook which is which.
• Place 6 drops of yellow dye in the bottle Ye;
• Dilute the food coloring with 30ml water;
• Repeat this procedure for both blue and green dye;
• In the last bottle (Mix) place 2 drops of each dye and diluted as usual;
• Prepare the coffee filter, cut it in 4 identical strips;
• Put a strip of paper in each bottle, as pictured;
• Use the paper clips to keep the paper in place;
• Wait until the dye reach the top of the paper, we wait 15min, may be more or less depends on the brand of the dyes.
• After the dye reach the top of the paper remove it from the cup and put it on a horizontal surface;
• Wait until it dries;
• Observe the color patterns.

What happens?
The water climbed the paper and the food coloring dissolved on it formed patterns in the paper.
In pictures you can see we used circle and strip paper, the results were exactly the same for the used colors.

Why?
Chromatography is, as its name indicates, writing (spelling) colors (chrome) and is one of the main techniques that biochemists use to separate mixtures.

First, before attempting to answer our question, it would be necessary to state three things:

• The first is that we must have a control, in this experiment a bottle with solvent without the dye, to exclude any possible interference of anything, We have done it, but does not appear in pictures. We did not observe any color band in this “blank”.
• The second is that the solutions were made with 6 drops of dye to 30 ml water, it’s possible you might get different results when using different trademarks and/or dilutions, so in science it is very important to control everything, even the brand of reagents.
• And thirdly, we have to study the individually solution behavior so we can interpret the Mix results.

Control: No bands or spots of any color.

Green dye: Shows three colors, blue on top of the paper, a broadband green and a darker line on the base. We could observe a yellow band between the larger green band and the darker line at the base.
In the label on the bottle we can read: ”Contains yellow dye and green dye“ that way is normal o have a green and a yellow band in the paper, but where did the dark line came from? A closer look give us the answer: the darker line is a dark blue zone. Blue? Yes blue. That’s because green is the mix of the blue and yellow color. 

Yellow dye: the coffee filter paper was completely yellow. With a yellow zone more pronounced in paper, yellow is a primary color, and in the label doesn’t say anything about any addition of another type of dye.

Blue dye: We can see that the filter has three distinct zones (note the small strip in the photo), back lit we see one of the area's violet (on the color wheel this is the result of mixing blue and magenta) the second zone is blue, and the third band is a second kind of  blue, lighter and more prevalent, one is cyan, and the other is an unknown color we would probably only find out for sure using more advanced analysis techniques.

On the blue label we can read: “contains blue dye and E122”. What is this E122? The website ukfoodguide.net describe it as a carmine food coloring, the presence of this E122 may explain the violet band observed at the base of the paper.




After observing and interpreting individual results we will then look to the mix filter:

One large blue zone followed by a green one. Between them we can see a faint yellow band, in the base we can’t see the violet line or brown stain which would be expected by the presence of green dye, instead we can observe a dark indistinguishable line. Back lit we can see some violet color, but nothing conclusive. Probably this phenomenon is due to the fact that the carmine E122 and the brown present at the bottom of the paper requires more time and /or longer/ different kind of  paper to separate and become visible.

The answer to the above question is “Yes it is”. However it is necessary to improve the used technique.

A step further:

• Improve the separation method:
• Using different dilutions;
• Different filter papers;
• Bigger filter papers;
• See if you can see these bands, eventually even be surprised by other bands that become visible.

Et voilá!
A true experience!

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!