​What are batteries?

Batteries containers made up of one or more cells, in which chemical energy is converted into electricity and used as a source of power. Electricity is defined as the flow of electrons through a conductive path, called a circuit Batteries have three parts: a cathode (positive), an anode (negative), and an electrolyte. The charged (cathode and anode) ends of a battery is what connects to the electrical circuit.

In this experiment, we’ll be focusing on how batteries are able to conduct electricity. As mentioned before, chemical energy is turned into electricity by allowing certain chemicals to come into contact with each other in a controlled environment. Most household alkaline batteries have zinc as the negative electrode and manganese (IV) oxide as the positive electrode with potassium hydroxide for its electrolyte. The electrolyte acts as a wall of sorts, keeping the anode’s electrons from moving to the cathode (which has less electrons). When a circuit is established, electrons will flow along the wire towards the positive end of the battery.

In terms of how this electricity is expressed, when a light is a part of the circuit, it will light up as electrons flow through it to get to the other end of the battery.

Adding in some citrus

Now that we have an idea about how batteries work, we can experiment with different objects to see if they’d make a decent battery. Today, we’ll be working with lemons to see if they can conduct electricity the same way household batteries do.

Author: Maddie Van Beek

Tomorrow is Valentine's Day! Today, we are going to perform some experiments on some Valentine's candy and make a DIY crystal Valentine gift for someone!

History of Valentine's Day
Valentine's Day started as a feast to honor Saint Valentinus. Watch the video below for a history of Valentine's Day! ​

Valentine's Day may also be associated with the ancient Roman Festival of Lupercalia, in which young men and women were paired up. Since the 14th century Valentine's Day has evolved to be a holiday that celebrates love. By the 18th century, people started expressing love through small gifts and cards called valentines.  

Candy Hearts Experiment
In this experiment, you will determine whether candy hearts react with baking soda or vinegar. You are looking for a chemical reaction.

A chemical reaction...
* Occurs between two or more atoms or molecules
* Causes bonds between atoms to break
* Forms new bonds
* Creates new molecules


Basically, two substances interact to create a new form or substance.


Read this link for more information on chemical reactions:

Now that you know a little bit about chemical reactions, let’s move on to our experiment!


YOU WILL NEED:
* Candy hearts (Sweethearts brand)
* Vinegar
* Baking soda
* Water
* Two bowls
* Glass
* Measuring cups


Here's what to do!
1. Place a few candy hearts in each bowl.
2. Add 1 cup water and 1 tablespoon baking soda to your glass. Stir until the baking soda dissolves.
3. Pour 1/2 cup vinegar into the first bowl. Observe what happens.
4. Pour 1/2 cup baking soda water into the second bowl. Observe what happens.
5. Which addition caused a chemical reaction, the baking soda water or the vinegar? Why do you think this is? Write down your thoughts.

So, you noticed that your candy hearts react with the baking soda water and not with the vinegar. What does that tell you? What else reacts with baking soda? Think back to other science experiments you may have done in the past. For more info, take a look at this blog we posted back in 2014: http://www.discoveryexpresskids.com/blog/use-vinegar-and-baking-soda-to-blow-up-a-balloon​

Now that you know candy hearts react with baking soda, you are going to figure out WHY they react with baking soda. What ingredient in a candy heart might be causing this reaction? Take a look at the ingredients on the back of your candy hearts package.

Candy hearts contain these ingredients:
* Sugar
* Corn syrup
* Dextrose
* Glycerine
* Artificial and natural flavors
* Gelatin
* Vegetable gums (tragacanth, xanthan, arabic)
* Citric acid
* Artificial colors (red 3, yellow 5, yellow 6, red 40, blue 1)
​
You are going to test each of these ingredients separately to see which one is causing the chemical reaction.


YOU WILL NEED:
* Muffin tin (or several small bowls)
* Baking soda
* Sugar
* Corn Syrup
* Lemon juice
* Glycerine
* Water
* Food coloring

Here's what to do!
1. Put one teaspoon of sugar in one muffin cup and label it “sugar.” Put one teaspoon of corn syrup in the second muffin cup and label it “corn syrup.” Continue this process with the lemon juice, glycerine, and food coloring.
2. Add 1/4 cup water to each ingredient. In the sixth muffin cup, add 1/4 cup plain water.
3. Stir each ingredient until it dissolves in the water.
4. Now you get to start testing!
5. Add a spoonful of baking soda to each muffin cup. What happens? Which one reacts?


You should have noticed that the muffin cup with the lemon juice produced fizzing bubbles! There’s your chemical reaction! Remember, lemon juice contains citric acid. The citric acid in the candy hearts is what caused them to react with the baking soda water in your first experiment. Baking soda is a base. When acids and bases are mixed together, they react. That reaction produces carbon dioxide gas. You saw that gas in the form of those fizzy bubbles.

Another acid-base reaction that you have probably seen before is between baking soda and vinegar. Mix them together for more fizzy fun!
​
Now that you've performed some experiments, you get to use your crafty skills to make a valentine decoration!


Crystal Heart
You are actually going to create a crystal decorative heart by first boiling borax and then letting it crystallize.

What is borax?

Borax (short for boric acid) is a white mineral that is often used for cleaning. In its natural form, it is actually a crystal. Large borax deposits are found in California and Turkey, but borax is also commonly found in Tibet, Romania, and Bolivia.
​
Borax crystal can be white or clear. 

To learn more about borax, click the link below.

What is crystallization?

We've seen crystallization in action when we created crystal egg geodes or when we made our own rock candy.

You are going to create a borax solution by adding borax to boiling water. When you add borax to water, it will dissolve. If you keep adding borax, eventually there will be a point that no more will dissolve. At this point, your borax solution is saturated. If you keep adding borax, it will just sink to the bottom and the solution becomes supersaturated. This means that the liquid in the solution contains more solute (borax) than it can hold. A supersaturated solution is unstable, so it produces a precipitate. A precipitate is a solid that is produced from a solution. In this case, the precipitate is your borax crystal.


YOU WILL NEED:
* Borax (Find it in the same area as the detergents in your local grocery store)
* Food coloring
* Pipe cleaner
* Water
* Saucepan
* Stove


Here's what to do! 

​1. Boil water in a saucepan on the stove. (Make sure you ask an adult for help)
2. While you’re waiting for the water to boil, create a heart (or whatever shape you want) out of your pipe cleaner. When you’re finished creating your shape, place it in a glass jar.
3. Once the water boils, add borax. Stir until the borax dissolves. Continue adding borax until it will no longer dissolve. You’ll know your solution is supersaturated when the borax just sinks to the bottom. Remove the solution from the stove and add food coloring (optional).
4. Pour the borax solution into the glass jar. Make sure your pipe cleaner shape is completely submerged.
5. Leave the jar undisturbed for 24 hours.
6. Check back the next day. What happened?! Dump the borax solution down the drain and remove your crystal heart.

Image and video credits
Yo Bo, 2013. Animated history of Valentine's Day. Uploaded from YouTube on 2/13/2017. https://youtu.be/sHmVFJ3QlPw

Evan-Amos, 2011. Image uploaded from Wikimedia Commons on 2/13/2017. 
https://upload.wikimedia.org/wikipedia/commons/thumb/9/9b/Necco-Candy-SweetHearts.jpg/1024px-Necco-Candy-SweetHearts.jpg File in the Public Domain. 

Dulyan, A., 2005. Borax crystals. Image uploaded from Wikimedia Commons on 2/13/2017. 
https://upload.wikimedia.org/wikipedia/commons/thumb/f/f7/Borax_crystals.jpg/800px-Borax_crystals.jpg File in the Public Domain. ​
​
References
​https://en.wikipedia.org/wiki/Valentine's_Day
​https://en.wikipedia.org/wiki/Borax
​http://www.kiddyhouse.com/Valentines/
http://inspirationlaboratories.com/valentine-candy-science-candy-heart-reactions/
http://inspirationlaboratories.com/valentine-candy-science-candy-heart-ingredients-experiment/
http://fun-a-day.com/candy-heart-experiments-valentines-day/
http://chemistry.about.com/od/valentinesdaychemistry/a/Borax-Crystal-Heart.htm

Author: Maddie Van Beek

You might think coffee tastes disgusting, but the majority of the adults in your life probably drink coffee in the morning! A big reason that people drink coffee in the morning is because of the benefits of caffeine. Caffeine is a substance in coffee (as well as some other beverages and food items) that is classified as a stimulant. This causes people to WAKE UP! when they drink their morning cup of coffee. If no one in your life drinks coffee, I’m sure you or a friend has had a caffeinated beverage such as Mountain Dew or Pepsi. Did you know that even chocolate has a small amount of caffeine? It’s true!
​
Our experiment today has less to do with coffee and more to do with the effects of caffeine on the body. In our activity, you will create an experiment to see the difference in effects between caffeinated and decaffeinated coffee on a variety of test subjects. Before we start that, let’s learn a little more about caffeine and what a stimulant does. ​

What is caffeine?
Caffeine is classified as a legal stimulant that appears in many beverages and foods that we consume. Check out the links below for information about how caffeine affects those who consume it.

http://kidshealth.org/teen/drug_alcohol/drugs/caffeine.html
http://science.howstuffworks.com/caffeine1.htm
 
What is a stimulant?
A stimulant is “a substance that raises levels of physiological or nervous activity in the body.” This means that stimulants make you more alert and energized, but also raises your heart rate and blood pressure.
 
How is coffee decaffeinated?
Decaf coffee doesn’t come from different “special” coffee beans. Normal coffee beans go through a decaffeination process in which steam or water is added that causes the bean to swell. This swelling allows for caffeine to be extracted. Read more in the link below.

http://coffeeandhealth.org/all-about-coffee/decaffeination/
 
Some people even say that caffeine can increase athletic performance! According to several sources such as
Runner's World, having caffeine before a workout can reduce an athlete's perceived exertion. Basically, you don't feel as tired. If you do take caffeine before working out, just make sure to also stay hydrated! 

Taking Pulse:
1. Find your artery on your wrist, right below your thumb.
2. Place two fingers of one hand over the other artery, as pictured above. (Do NOT use your thumb, as it has its own pulse. 
3. Count the beats for 10 seconds, then multiply by 6 to get the beats per minute. 

Now you can get started on your experiment! 

1. Gather 10 test subjects. A higher number is always better to get more accurate results, so if you can get more participants, go ahead! When you ask your subjects to participate, make sure you tell them to refrain from eating or drinking for two hours before the test. Why do you think this would matter?
2. Write your test subjects’ names on small slips of paper. Fold the slips and put them in a bag.
3. Draw out five names. These five will receive regular coffee.
4. Draw out the last five names. These five will receive decaf coffee. They are receiving a placebo. This means that they think they are receiving the regular treatment, which is normal caffeinated coffee, but they are really receiving decaffeinated coffee. Make sure you do not tell your participants whether they are receiving regular or decaf!
5. Write your test subjects’ names on the coffee cups.
6. Brew a pot of decaf coffee and pour it into the cups of the last five names you drew.
7. Brew a pot of regular coffee and pour it into the cups of the first five names you drew.
8. Now it’s time for testing!
9. Before you test your subject’s pulse, ask them about their normal caffeine consumption. Take notes on their response. Take your subject’s pulse before you give them any coffee. Write down the result.
10. Give your subject the coffee. Take their pulse 5, 10, and 15 minutes after drinking the coffee.
11. Move on to the next subject and repeat steps 9 and 10 until you are finished with all 10 participants.
12. Graph the pulse for each participant. The X-axis should be time and the Y-axis should be pulse.
13. Analyze your results. Trace your graphs for caffeinated coffee participants in green. Trace your graphs for decaffeinated coffee participants in red. Do the green graphs look different than the red ones? What does this tell you about caffeine’s effect on the body?
14. Look at the graphs again and trace the regular caffeine consumers in blue. Do these graphs look different from those who are not regular caffeine consumers? Did caffeine affect non-users more so than regular users?
15. How else could you test caffeine? Example: Have runners who regularly use caffeine run a mile without caffeine and record their time, pulse, and perceived exertion. The next day, repeat the process with the same subjects after they drink a cup of coffee. Does the coffee make a difference?

Schorzman, J., 2005. A small cup of coffee. 
https://upload.wikimedia.org/wikipedia/commons/thumb/4/45/A_small_cup_of_coffee.JPG/800px-A_small_cup_of_coffee.JPG File used in accordance with the 
Creative Commons Attribution 2.0 Generic License. Image was not changed. 

Jynto, 2011. Caffeine (1) 3D ball. 
https://upload.wikimedia.org/wikipedia/commons/thumb/0/05/Caffeine_%281%29_3D_ball.png/800px-Caffeine_%281%29_3D_ball.png File in the Public Domain. 

Haggstrom, M., 2012. 
https://upload.wikimedia.org/wikipedia/commons/thumb/0/07/Health_effects_of_caffeine.svg/800px-Health_effects_of_caffeine.svg.png File in the Public Domain. 

Pulse photo and running photo provided by Maddie Van Beek.