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How does salt affect ice? 

11/28/2016

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Author: Maddie Van Beek

It's almost December and the weather will be getting colder! In Fargo, the roads and sidewalks can get pretty icy, so people take extra care with driving and walking in the winter. ​Have you ever seen salt on the sidewalks in the wintertime? Most of you probably know that salt causes ice to melt. People sprinkle salt on icy sidewalks to make them less slippery. Have you ever wondered how that works? That’s what we are going to find out today!
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Sodium Chloride, otherwise known as common table salt.
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This is a single grain of table salt under a microscope!
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This machine is called a gritter. This is a gritter about to spread salt on the roads in Germany.
Why does salt melt ice?

When you dissolve salt in water, the water is harder to freeze. Usually, water freezes at 32 degrees Fahrenheit (0 degrees Celsius). When you add salt to water, it has to be colder than 32 degrees Fahrenheit in order to freeze. Thus, adding salt to water lowers the freezing temperature.
​
Watch this video to find out more about the science behind why salt melts ice: 
​
Check out this link for more information: 
http://science.howstuffworks.com/nature/climate-weather/atmospheric/road-salt.htm
 
Now that you know why salt melts ice, let’s test it out!
 
YOU WILL NEED:
  • Clear glass
  • Water
  • Ice cubes
  • String
 
Here’s what to do!
  1. Fill your glass about ¾ full with water.
  2. Add about 5 ice cubes.
  3. Cut a piece of string about 1 foot long.
  4. Dangle the string into the water and try to catch an ice cube. When you lift the string out, do any ice cubes stick to it?
  5. Let’s try it again. Dangle the string into the water over the ice cubes. This time, sprinkle some salt over the ice cubes. Wait a few seconds, then lift the string up. Do any ice cubes stick this time? Yes! Why did the salt make the difference? Remember, salt causes ice to melt! When you sprinkled salt on the ice cubes, they began to melt, but the water around it quickly refroze. The refreezing trapped the string onto the surface of the ice cubes. See how many ice cubes you can catch at once!
  6. Does more salt change the effect? Try it out!
 
Now that you know how salt affects ice, use this same science to make your own slushy without the aid of a freezer!
​
YOU WILL NEED:
  • Fruit juice
  • Ice cubes
  • 1 Gallon Ziploc bag
  • 1 smaller Ziploc bag
  • Salt
 
Here’s what to do!
  1. Carefully pour fruit juice into the smaller bag and seal it shut.
  2. Put ice cubes into the gallon-sized bag and add the salt.
  3. Place the sealed smaller bag inside the gallon-sized bag.
  4. Seal the larger Ziploc bag shut.
  5. Shake it up!!!
  6. Remember, salt lowers the freezing temperature of ice, so it causes the ice to melt. As the ice melts, the salty mixture also becomes colder… just cold enough to freeze up your fruit juice!
  7. Once your fruit juice reaches the desired slushy consistency, place the bag in the sink, remove the smaller bag from the larger one and rinse it off with cold water.
  8. Open your fruit juice bag and enjoy your homemade slushy!
 
References
http://www.sciencekiddo.com/salt-melts-ice-experiment/
http://www.sciencekiddo.com/fruity-ice-slush/
https://www.highlightskids.com/science-questions/how-does-salt-melt-ice-and-snow
http://science.howstuffworks.com/nature/climate-weather/atmospheric/road-salt.htm
​https://en.wikipedia.org/wiki/Salt
Image and video credits, in order of appearance:

Soric, D., 2009. Salt shaker on a white background. Image uploaded from Wikimedia Commons on 11/27/2016. https://upload.wikimedia.org/wikipedia/commons/thumb/7/78/Salt_shaker_on_white_background.jpg/800px-Salt_shaker_on_white_background.jpg File used in accordance with the 
Creative Commons Attribution 2.0 Generic Image was not changed. 

Chhe, 2009. SEM image of a grain of table salt. Image uploaded from Wikimedia Commons on 11/27/2016. https://upload.wikimedia.org/wikipedia/en/thumb/9/9b/Single_grain_of_table_salt_%28electron_micrograph%29.jpg/800px-Single_grain_of_table_salt_%28electron_micrograph%29.jpg File in the Public Domain. 

Heidas, 2005. Schneepflug strasse hinten. Image uploaded from Wikimedia Commons on 11/27/2016.
https://en.wikipedia.org/wiki/Winter_service_vehicle#/media/File:Schneepflug_Strasse_hinten.jpg File used in accordance with the CC Attribution-Share Alike 3.0 Unported. Image was not changed

Reactions, 2015. How does salt melt ice? Video uploaded from YouTube on 11/27/2016. https://youtu.be/JkhWV2uaHaA
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Thanksgiving History and Science

11/21/2016

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As you all know, this Thursday is Thanksgiving! Today, we are going to research the history of Thanksgiving, test out Squanto’s gardening methods, and learn how to track our daily diets! 

We all picture the first Thanksgiving as a day spent with the pilgrims and the Native Americans chowing down on a Thanksgiving feast. Did you know that there were actually several “first Thanksgivings?” 

Learn more about the American history of Thanksgiving!
American History of Thanksgiving
What were the other “first Thanksgivings?” 

Did you know November is National American Indian and Alaska Native Heritage Month? What a great time to learn more about Native American history and culture, especially as we celebrate Thanksgiving! 

More information on Native American histories and tribes:
Native American Tribes
While Thanksgiving is a great time to spend with family and celebrate an abundance of food, it is also important to remember the roots of Thanksgiving. We don’t often remember the Wampanoag’s point of view during the first Thanksgiving. Take some time to consider how the Wampanoag’s might have felt when the first white settlers arrived. 

Quickwrite: Write in the perspective of a member of the Wampanoag tribe when the white settlers arrived at Plymouth. How do you feel?
A Wampanoag Viewpoint
The Wampanoags were the Native American tribe that befriended the settlers and accompanied them in the “first Thanksgiving” meal. Squanto was one of the Wampanoags that is well known for aiding the settlers in their time of need. One way Squanto helped out was to assist them in growing corn by using fish. Check out Squanto’s gardening methods!
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Hypothesize: How might fish emulsion help or harm the growth of a corn plant? Will it really make that much of a difference? 

YOU WILL NEED:
  • Water
  • Corn seeds
  • Fish emulsion
  • Milk cartons 
  • Scissors
  • Soil

YOU WILL DO:
  1. Use the scissors to cut the top off of two half-pint milk cartons (ask an adult for help).
  2. Fill both cartons with soil. 
  3. Read and follow the directions on your corn seed packet to plant one seed in each carton. 
  4. Push the corn seed 1-2 inches into the surface of the soil. 
  5. Label one milk carton “Control” and one milk carton “Variable.” 
  6. Your control plant will be watered only with plain water. 
  7. Your variable plant will be watered with a mixture of water and fish emulsion. 
  8. Follow the package instructions on the fish emulsion to dilute it with water. 
  9. Water your Control plant with water and your variable plant with the diluted fish emulsion. 
  10. Place both plants in the sun. 
  11. Water both plants each day and record your observations in a daily log. 
  12. Measure both plants’ growth each day and record. 
  13. What differences do you see in the two plants? 
  14. Create a graph at the end of your experiment to show the differences in growth. 
  15. Reflect: How did the fish emulsion make a difference in the growth of the variable plant? Why do you think this is? 

Now that we’ve talked about GROWING food, let’s think about EATING food! 

Did you know that the average American eats over 4,000 calories on Thanksgiving day?! Wow! To put that in perspective, the average diet is only about 2,000 calories/day. ​
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Watch this video to understand calories in a Thanksgiving Day Meal: 
Now, here’s an idea of how many calories you should have in a day:
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http://www.choosemyplate.gov/weight-management-calories/calories/empty-calories-amount.html
Keep in mind that physical activity increases your caloric need! Think of your body like a car--let’s say your car holds 15 gallons of gas. You fill it up with 15 gallons. If your car just sits in the garage, it doesn’t lose any gas, but if you go for a drive, it burns gas. Is your tank still full after a 200-mile drive? No! If you want your gas tank to be full, you would have to refuel. It’s the same way with your body! For example, if my daily caloric need is 2,000 calories, and I burn 500 calories on a run, then I should actually consume 2,500 calories so my body still gets the calories it needs to stay fueled.

Here’s more information about what you can do to have a healthy, balanced diet:
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Example of a Food Plan
How many calories are in your daily schedule? 

Are you eating a balanced diet? 

Create a food diary to see what your diet is really like! The point is not for you to count every calorie you eat--the point is that when we pay attention to what we put into our bodies, we are more conscious of what we are consuming. Being cognizant of the way you eat will help you make healthy choices for YOUR body! 

Predict: 

How many calories do you think you eat in a normal day? 

Do you think you have a balanced diet? 

What do you think you eat too much of? 

What do you think you don’t get enough of? 

Each day for one week, write down everything you eat for breakfast, lunch, dinner, and snacks. Each time you write down a food, determine whether it is a fruit, vegetable, grain, dairy, protein or fat. 

At the end of the week, look back at your food chart and reflect on your diet. About what percentage of your diet is protein? Fat? Does your daily diet look like the My Plate recommendation? Are you getting enough fruits and vegetables? Being conscious of your diet is the first step to taking care of a happy, healthy body! 




Other References:

http://www.educationworld.com/a_lesson/02/lp286-03.shtml

http://www.loc.gov/teachers/classroommaterials/presentationsandactivities/presentations/thanksgiving/celebration.html#

http://www.tolatsga.org/Compacts.html#Wampanoag

Image and Video Credits, in order of appearance:

Brownscombe, J.A., 1914. The first Thanksgiving at Plymouth. Image uploaded from Wikimedia Commons on 11/21/2016.
https://upload.wikimedia.org/wikipedia/commons/thumb/9/98/Thanksgiving-Brownscombe.jpg/1024px-Thanksgiving-Brownscombe.jpg File in the Public Domain. 

1910. Squanto teaching. Image uploaded from Wikimedia Commons on 11/21/2016. 
https://upload.wikimedia.org/wikipedia/commons/b/bc/Squantoteaching.png File in the Public Domain. 

Franske, B., 2002. Traditional Thanksgiving. Image uploaded from Wikimedia Commons on 11/21/2016. https://upload.wikimedia.org/wikipedia/commons/thumb/0/04/TraditionalThanksgiving.jpg/1024px-TraditionalThanksgiving.jpg File used in accordance with GNU Free Documentation License. Image was not changed. 

Healthcare Triage, 2014. How many calories are in your Thanksgiving dinner? Video uploaded from YouTube on 11/21/2016. 
https://youtu.be/PEWCUVnng6Q

USDA, 2014. ChooseMyPlate.gov. ​https://www.choosemyplate.gov/

​
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Cranberry Science for Thanksgiving!

11/14/2016

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Author: Maddie Van Beek

​Thanksgiving is coming up! One of the most popular Thanksgiving staples are cranberries. Cranberries are small, red berries that grow on a shrub. They’re usually sweetened into a sauce or jam, often for Christmas or Thanksgiving.
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At the holidays, you might see whole cranberries, jellied cranberries, or cranberry sauce. How can we use cranberries for science? Let’s find out!

Cranberry Reactions

Watch cranberry juice react with baking soda and lemon juice!

There are two reasons that cranberries are going to react in our experiment today. One, cranberries are acidic. As you might know, when acids and bases meet, a chemical reaction takes place. You’ve seen this happen when you mix baking soda (a base) and vinegar (an acid). What happens? Lots of fizzing and bubbles! Remember, those bubbles are releasing carbon dioxide gas as a product of the reaction. The second reason that you’ll see a special reaction from cranberries is because of their pigment, anthocyanin. Anthocyanin is what makes cranberries their deep red color. When the acidity changes in the juice, anthocyanin reacts by changing color! Today, you’re going to mix cranberry juice with baking soda and lemon juice to see how these ingredients react with each other.
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YOU WILL NEED:
* Cranberry sauce, juice, or whole cranberries
* Baking soda
* Lemon juice
* Glass or container
* Measuring spoons


1. If you’re using cranberry sauce, make sure it’s thawed out and in liquid form. If you’re using whole cranberries, mash them up and add a little hot water to get a good amount of juice.
2. Pour the cranberry juice into a glass. You should have at least one cup of juice.
3. Predict what will happen when you add a spoonful of baking soda to the glass of cranberry juice.
4. Add the baking soda and observe what happens. Record your observations.
5. Predict what will happen when you add lemon juice to the cranberry juice.
6. Add two tablespoons of lemon juice and observe the reaction! What happened?
7. Record your findings.
8. Extension: Add different amounts of baking soda or lemon juice. Does that make a difference? Can you get the color to change even more? What happens if you add baking soda and lemon juice at the same time?


Cranberry Building

In this activity, you will use cranberries to build the tallest structure possible!


YOU WILL NEED:
* Fresh, whole cranberries
* Toothpicks


Here’s what to do!
1. Unwrap your cranberries.
2. Connect two cranberries with a toothpick.
3. Continue building and connecting cranberries to build whatever structure you want. See how tall you can make your building before it tips over!
4. Test out the strength of your structure by setting an object on top. See how much your structure will hold!
5. Challenge: Try rationing yourself to only 20 toothpicks. Using those 20 toothpicks, what shape will create the strongest structure? Try a few different structures and test which one is the strongest!


Cranberry Sauce Recipe
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Here’s a great cranberry sauce recipe that you can use for the holidays! Impress your family by helping out with this traditional treat!


YOU WILL NEED:
* 12 ounce bag of cranberries
* Sugar
* Orange zest
* Pepper
* Water
* Salt
* Pan
* Stove

Here's what to do!
1. Empty your cranberries into a saucepan.
2. Transfer 1/2 cup of the cranberries into a small bowl. 
3. Add 1 cup sugar, 1 strip orange zest, and 2 tablespoons water to the saucepan. 
4. Stir over low heat until the cranberries soften and the sugar dissolves.
5. Increase to medium heat cook until cranberries burst. 
6. Reduce to low heat and add the 1/2 cup of reserved cranberries. 
7. Add sugar, salt, and pepper to taste. 
8. Let cool to room temperature before serving.  

Recipe from: 
http://www.foodnetwork.com/recipes/food-network-kitchens/perfect-cranberry-sauce-recipe.html

Image credits, in order of appearance:
Weller, K., 2005. Cranberry bog. Image uploaded from Wikimedia Commons on 11/13/2016. 
https://upload.wikimedia.org/wikipedia/commons/thumb/3/3a/Cranberry_bog.jpg/1024px-Cranberry_bog.jpg
File in the Public Domain. 

Cjboffoli, 2010. Cranberries20101210. Image uploaded from Wikimedia Commons on 11/13/2016. 
https://upload.wikimedia.org/wikipedia/commons/thumb/4/45/Cranberries20101210.jpg/1024px-Cranberries20101210.jpg ​File used in accordance with the Creative Commons Attribution-Share Alike 3.0 Unported license. No changes were made.

Veganbaking.net, 2008. Cranberry sauce. Image uploaded from Wikimedia Commons on 11/13/2016. 
https://upload.wikimedia.org/wikipedia/commons/thumb/0/07/Cranberry_Sauce_%283617909597%29.jpg/800px-Cranberry_Sauce_%283617909597%29.jpg 
File used in accordance with the Creative Commons Attribution 2.0 Generic license. No changes were made.

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Science of starch: Make your own gravy for Thanksgiving!

11/6/2016

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Author: Maddie Van Beek

In just a few weeks, most of the country will celebrate Thanksgiving by having a turkey dinner. Traditionally, Thanksgiving dinners aren’t complete without mashed potatoes and gravy, but gravy is notoriously tricky to thicken to the right consistency. So how exactly do you make gravy, anyway? Let’s find out! ​
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Gravy is traditionally made from the turkey drippings. Some people swear by adding flour to the turkey drippings, while some say that the addition of corn starch is the secret to perfect gravy. The truth is, either ingredient will work to thicken gravy because both corn starch and flour contain starch, which is the one necessary ingredient to thickening a liquid such as gravy. 

Remember, just last week we learned about starch! We used potato starch to create our own "magic mud!" If you missed it, check it out here: ​http://www.discoveryexpresskids.com/blog/october-31st-2016

How does starch work? 
Starch will thicken a liquid, but the catalyst for starch to thicken is heat (Remember, a catalyst is a helper that gets a reaction going). When heat is applied, starch grains take in liquid and swell, causing that liquid to become thicker. Without heat, starch grains won’t take in enough liquid to make a difference. 

To learn more, check out the following two links: 
http://www.thekitchn.com/food-science-how-starch-thicke-83665 
http://www.scienceinschool.org/2010/issue14/starch

​

Picture
Structure of Amylose, one of two components of starch.
Picture
Structure of Amylopectin, the second component of starch.
Now that you know more about starch, let's make some gravy!

Make your own gravy

What works better, flour or corn starch? Predict which ingredient will thicken the water quickest. You don’t have to go to the trouble of making real gravy to test out these ingredients. Just use warm water, and you’ll get a similar effect. 



YOU WILL NEED:
  • Two mugs or small bowls
  • Water
  • Corn starch
  • Flour


Here’s what to do: 
  1. Put 1/2 cup of water in each mug. 
  2. Microwave both mugs of water for about 1 minute (the water should be warm, not boiling). 
  3. Add 1 tablespoon of corn starch to the mug on the left, and 1 tablespoon of flour to the mug on the right. 
  4. Stir both mugs. Did the consistency change? 
  5. Keep adding flour and corn starch 1 tablespoon at a time, stirring after each spoonful. How many tablespoons of corn starch does it take for the liquid to get noticeably thicker? How many tablespoons of flour does it take? 
  6. You should have noticed that it took way more flour (about twice as much) to get the same thickness as the mug with corn starch. This is because corn starch is 100% starch, but flour is a mix of starch and protein. 


If you continue to add starch to water, you’ll get a gooey substance that’s fun to play with. You can roll the starchy goop into a ball, but when you quit moving it will slip through your fingers like liquid! 

​If you’re looking for some messy fun, try out the first slime recipe in our blog: 
http://discoveryexpress.weebly.com/blog/two-times-the-slime-fun-with-polymers (you can continue to use corn starch instead of liquid starch). 



OR


If you want to try to make your own gravy, here’s a recipe to test out:
​http://saucepankids.com/index.php/2012/07/real-gravy-no-bisto-recipe/



Now that you know a little bit about starch and its properties, lets move on to our next activity. 


A few weeks ago, we did an activity called Iodine Clock Reaction. 


If you missed it, check it out here: http://discoveryexpress.weebly.com/blog/iodine-clock-reaction


In that activity, we combined iodine, starch, vitamin C, and hydrogen peroxide. Because of a chemical reaction, clear liquids suddenly became dark blue! In our activity today, we will use iodine to test certain substances for starch. If the substance contains starch, BINGO! the iodine will turn blue.
Picture
Granules of wheat starch that have been stained blue with iodine.
YOU WILL NEED:
  • Iodine tincture (http://www.amazon.com/Cumberland-Swan-Iodine/dp/B00I3LNFT6)
  • Water
  • Dropper
  • Plastic cup
  • Polystyrene (styrofoam) cup
  • Apple
  • Potato
  • Bread
  • Paper
  • Tissue


Here’s what to do! 
  1. Create a work space where you can get messy. Either grab a large tray or cover your space with plastic or newspaper. This will be your testing area. 
  2. Dilute the iodine with water. The ratio of iodine to water should be 1:10. (For example, you could use 1 tablespoon of iodine and 10 tablespoons of water). If you need help, ask an adult! 
  3. Create a chart of substances that you will test for starch. You are going to test a plastic cup, styrofoam cup, apple slice, potato slice, piece of bread, paper, and tissue. If you want to test even more, add them to your chart. Then predict whether you think each substance has starch in it. Leave your final column blank to record your test results. Your chart may look something like this: 
Picture
4. Now that you have your iodine solution and your chart prepared, you’re ready to start testing materials! 

5. Fill your dropper with iodine solution. 

6. Place your first substance in your testing area. Squeeze a drop of iodine solution onto your first substance and observe. Did the iodine change colors? If not, the substance does not have starch. If the iodine changed to a dark blue, the substance must have starch! Fill in your chart after you test each material. 

7. After your testing is over, record your final observations. Were your predictions right? Were you surprised by your results? 

​
References: 
http://www.thekitchn.com/food-science-how-starch-thicke-83665
http://www.scienceinschool.org/2010/issue14/starch
http://www.primaryscience.ie/media/pdfs/col/exploring_starch.pdf
Image and video credits, in order of appearance

Rehemtulla, M., 2009. RoastTurkey. File uploaded from Wikimedia Commons on 11/6/2016. 
https://upload.wikimedia.org/wikipedia/commons/thumb/1/11/RoastTurkey.jpg/1024px-RoastTurkey.jpg​
File used in accordance with the Creative Commons Attribution 2.0 Generic license. No changes were made.

NEUROtiker, 2007. Amylose2.  File uploaded from Wikimedia Commons on 11/6/2016. 
https://upload.wikimedia.org/wikipedia/commons/thumb/2/21/Amylose2.svg/486px-Amylose2.svg.png 
​This file is in the Public Domain.

NEUROtiker, 2008. Amylopektin Sessel, 2008. File uploaded from Wikimedia Commons on 11/6/2016. 
https://upload.wikimedia.org/wikipedia/commons/thumb/8/80/Amylopektin_Sessel.svg/451px-Amylopektin_Sessel.svg.png This file is in the Public Domain. 

Yuri, K., 2006. Wheat starch granules. File uploaded from Wikimedia Commons on 11/6/2016. 
https://upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Wheat_starch_granules.JPG/800px-Wheat_starch_granules.JPG This file is in the Public Domain. ​

​Chart created by Maddie Van Beek. Uploaded on 11/6/2016. 
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