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How effective is your sunscreen? 

7/25/2016

2 Comments

 
Author: Maddie Van Beek
Picture
Image 1
It has been a HOT week in Fargo, North Dakota! Almost every day the temperature has reached 90 degrees fahrenheit. When the sun is out (and even when it’s not) it’s very important to protect your skin! While the sun gives us many benefits such as light and Vitamin D, it can also be very harsh on your skin.


Have you ever gotten a tan line from being out in the sun? When you’re exposed to Ultraviolet rays from the sun, your skin produces melanin. That melanin is a pigment that makes your skin darker. In the picture below, you can see the difference between the area of this person’s arm that was exposed to the sun and the area that was covered. The exposed area has produced more melanin and thus is tanner. ​
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Image 2
While getting tan isn’t a bad thing, you want to protect your skin from getting burned. When your skin gets red rather than tan, it’s been burned. While getting burned once or twice isn’t the end of the world, continued sun burns could cause skin damage or increase your risk of skin cancer. 


How can you protect your skin? 
You can be proactive and avoid getting burned by wearing protective clothing that has a high UPF rating. You can also apply sunscreen to protect your skin, but make sure you do this BEFORE you go outside and reapply throughout the day. The Skin Cancer Foundation recommends that you reapply every two hours, just to be safe. 


What’s the difference between SPF and UPF? 
UPF is the rating for clothing that protects you from the sun while SPF is the rating system for sunscreen. SPF stands for Sun Protection Factor while UPF stands for Ultraviolet Protection Factor. The SPF rating measures the amount of time it takes for your skin to redden in the sunlight, while UPF measures the amount of the sun’s UV rays that can penetrate the clothing. If a shirt has a UPF of 35, then 1/35th of the UV rays are making it through the fabric. 


How does sunscreen block the sun? 
There are a few different types of sunscreen, but all sunscreen does at least one of two things. It either contains chemical compounds that absorb the UV light from the sun, or it contains ingredients such as zinc oxide or titanium dioxide that act as a block that reflects the UV light from your skin. 


Check out this link to learn more about the science of sunscreen: ​
The Science of Sunscreen
Now that you know more about sun protection, let’s get started on our activity! You are going to actually test the effectiveness of sunscreen. Don’t test this out on your skin! We are going to use special sun-sensitive paper to test how well different sunscreens work. 


Test the Effectiveness of Sunscreen


YOU WILL NEED: 
  • Sunscreen of different SPF ratings
  • Sun-sensitive paper (You can buy on Amazon here: https://www.amazon.com/Nature-Print-Paper-inch-Pack/dp/B0042SSSVE) 
  • Ziplock bags
  • Tablespoon
  • A sunny day


Here’s what to do! 
  1. Make sure you start your experiment inside. You are using special paper that reacts to the sunlight, so you need to keep the paper out of the sun until it’s testing time. 
  2. Gather sunscreens of various SPF ratings. For example, you could choose 15 SPF, 30 SPF, 50 SPF and 70 SPF. 
  3. Remove a piece of sun-sensitive paper and write “control” on the back. Next, place it inside a ziplock bag. This piece of paper gets no treatment from any sunscreen. 
  4. On the back of the second sheet, write “15 SPF” and place it inside a ziplock bag. Smear a tablespoon of 15 SPF sunscreen all over the surface of the bag. 
  5. On the back of the third sheet, write “30 SPF” and place inside a ziplock bag. Smear a tablespoon of 30 SPF sunscreen all over the surface of the bag. 
  6. Continue with this process until you have created a bag to test each variety of sunscreen. 
  7. Carry each bag outside and set in the sun with the sunscreen-smeared side facing up. 
  8. After about five minutes, you can go get your bags and bring them inside. Submerge each bag in a tub of water and rinse off the sunscreen. 
  9. Analyze each piece of paper. The white areas of the paper were blocked by the sunscreen, while the blue areas of paper were not. What do you notice? Do all the sheets look the same? Did a higher SPF rating better protect your paper? Write down your observations. 


Now you know why wearing a high SPF sunscreen is so important! 


Extensions:
  1. Some people actually forgo sunscreen and use tanning oil or baby oil to enhance their tan. Test out a few different oils to see what happens. Do any of them provide any protection? 
  2. Are some sunscreen brands better than others? Choose three different brands of the same SPF rating and compare their effectiveness. 
  3. Clothing also has some sun protection, but some fabrics block more sun than others. Try putting the paper inside a few different items of clothing and set in the sun to test how well clothing could protect you. 


References:
  • Skin Cancer Foundation, 2014. Get in on the trend. http://www.skincancer.org/prevention/sun-protection/clothing/get-in-on-the-trend
  • Grifantini, 2010. How does sunscreen work? http://www.livescience.com/32666-how-does-sunscreen-work.html
  • 2016. Sunscreen. https://en.wikipedia.org/wiki/Sunscreen
  • Mauk, 2013. Why does the body tan? http://www.livescience.com/32493-why-does-the-body-tan.html


Image credits in order of appearance: 
  • Hudson, Dawn. Sunglasses and lotion clipart. Uploaded from publicdomainpictures.net on 7/24/2016. http://www.publicdomainpictures.net/view-image.php?image=79912&picture=sunglasses-and-lotion-clipart File released into public domain. 
  • Onetwo1, 2007. Tanned arm. Uploaded from Wikimedia Commons on 7/24/2016. https://upload.wikimedia.org/wikipedia/commons/thumb/6/65/Skin_tanning.JPG/1280px-Skin_tanning.JPG File used in accordance with the Creative Commons Attribution-Share Alike 3.0 Unported license.
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Make your own sugar glass!

6/13/2016

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Author: Maddie Van Beek

​Have you ever wondered how glass is made? Glass can form naturally over time or it may be man-made. Most of the glass you see every day is man-made, but all glass has the same main ingredient--sand! The sand must be heated to extremely high temperatures in order to melt, and that melted sand changes from opaque to transparent as it cools.


Below is a picture of volcanic glass. This glass was formed from sand that was rapidly heated in a volcano and then cooled.

Picture
http://www.whoi.edu/cms/images/volcanic_glass_78430.jpg
While naturally occurring glass is formed by sand that has been heated to an extremely high temperature, man-made glass contains other added ingredients such as sodium carbonate and calcium carbonate that make the sand melt at a lower temperature. Without these ingredients, we would have to use a lot more energy to create glass!


Check out this video to watch how glass is made:
How Glass is Made
We aren’t going to make real glass today, but we are going to use the same concepts to make sugar glass!


How are we going to do this? When you add sugar to water and stir, the sugar dissolves and creates a sugar solution. You may have experienced this if you’ve ever made Kool-Aid--the powder disappears into the water and seems to become one with the liquid. If you mix water and sugar together but then leave the sugar solution alone until the water evaporates, sugar that was once dissolved will remain! Adding a few simple ingredients in this activity (corn syrup and cream of tartar) prevents the solution from crystallizing back into sugar and leaves you with a transparent solid--sugar glass!
Picture
https://img-global.cpcdn.com/001_recipes/f71e13b5b6bdefbe/664x470cq70/photo.jpg
YOU WILL NEED:
* Granulated sugar
* Cream of Tartar (you can find this in the spice section of any grocery store)
* Water
* Light corn syrup
* Measuring cups/spoons
* Cookie sheet
* Saucepan
* Stove
* Candy thermometer
* Stirring spoon
* Non-stick cooking spray
* Food coloring
* Fork or toothpick


Here’s what to do!
1. Use measuring cups and spoons to measure out 1 3/4 cup granulated sugar, 1 cup water, 1/2 cup light corn syrup, and 1/8 teaspoon cream of tartar.
2. Combine all ingredients in a saucepan.
3. Spray your cookie sheet with non-stick cooking spray and set it off to the side.
4. Turn the burner on low/medium in order to heat your ingredients slowly. If the solution gets too hot, it will caramelize and turn a yellowish color. Stir constantly as the solution heats up.
5. Once your solution turns clear, you can stop stirring and place the candy thermometer in the saucepan. The solution will begin to boil slowly, but that’s okay. Just make sure not to get splashed!
6. Keep a close eye on the thermometer and remove the saucepan from the burner once the solution reaches the hard crack stage (between 300 and 310 degrees Fahrenheit).
7. Carefully pour the solution into the cookie sheet.
8. Now let your creativity shine! Sprinkle your choice of food coloring onto the cookie sheet of syrup. Next, use a fork or toothpick to swirl the dots of color throughout the syrup. Have fun with it! Just BE CAREFUL to not touch the hot syrup!
9. Leave the cookie sheet in a safe place to cool down. Check back a few hours later and remove your sugary, beautiful creation!


For more science activities that involve crystallization, check out:
* http://www.discoveryexpresskids.com/blog/sedimentation-and-crystallization-how-to-make-egg-geodes
* http://www.discoveryexpresskids.com/blog/sweet-solutions-rock-candy


For more science activities involving baking/cooking, check out:
* http://www.discoveryexpresskids.com/blog/science-of-baking-whats-the-difference-between-baking-soda-and-baking-powder
* http://www.discoveryexpresskids.com/blog/the-science-of-meat-tenderizer


References:
* http://www.instructables.com/id/How-to-make-Sugar-Glass/
* http://science.howstuffworks.com/innovation/28024-some-assembly-required-how-glass-is-made-video.htm
* http://www.explainthatstuff.com/glass.html
* http://www.stevespanglerscience.com/lab/experiments/stained-glass-sugar/
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Science of Baking: What's the difference between baking soda and baking powder? 

5/3/2016

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Author: Maddie Van Beek

Did you know baking involves science? It’s true! You use many of the same skills when you bake that you also use when you conduct a science experiment. You have to measure, pay attention to detail, and carefully follow directions. Altering your recipe could lead to an undesirable result!


Today, you’re going to test the differences between baking soda and baking powder.


Baking soda is... sodium bicarbonate (or NaHCO3 as a chemist would write). Simply put, it’s a base that reacts immediately with anything acidic. Can you think of a few examples of something that contains an acid?

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Do you remember any baking soda activities? We’ve seen baking soda react in many different experiments, such as when we made exploding glow-in-the-dark art (www.discoveryexpress.com/blog/exploding-glow-in-the-dark-art) or created New Year’s foam eruptions (www.discoveryexpress.com/blog/happy-new-year)!


Just as a reminder (and a fun break), let’s try it out again!


YOU WILL NEED
* Baking soda
* Deep pan
* Vinegar


Here’s what to do!
1. Measure out 1/2 cup of baking soda and dump it into the center of your pan.
2. Measure 1/2 cup of vinegar and pour it over the baking soda.
3. What happens?! Fizzy bubbles! You should have seen the baking soda and vinegar react and suddenly produce white fizz. That fizz is a bunch of tiny bubbles of carbon dioxide gas. Why does that happen? Baking soda is base, and vinegar is an acid. When the two mix, they create a chemical reaction!


Now, what do you think will happen when you mix baking powder with vinegar? Test it out! Follow steps 1-3, except substitute baking powder for baking soda. Reflect on your results. Did baking powder react the same way baking soda did? Why do you think this happened?


Baking powder is... baking soda PLUS other ingredients. So is baking powder still a base? Sort of. It contains the base sodium bicarbonate, but it also contains acids. When the baking powder is dry, the base and acid do not mix. Think of our experiments when we’ve used Alka-seltzer®; it’s very similar in the sense that the base and acid stay separate when dry, but react when mixed in water. When you mix baking powder into wet ingredients it begins to react, but ONLY when it reaches the right temperature.
Picture
http://ichef.bbci.co.uk/food/ic/food_16x9_608/foods/b/baking_powder_16x9.jpg
Takeaway: Both baking soda and baking powder create chemical reactions in recipes, but baking powder has a prolonged reaction while baking soda has an immediate reaction.


Lastly, think about what baking soda and baking powder actually DO when they react in your recipes. When carbon dioxide gas is released, how might that affect the dough?
Picture
https://bakeryboyblog.files.wordpress.com/2010/12/5-bread-ornament-dough-rising.jpg
Yes... it RISES!


Now that you understand the ways that baking powder and baking soda react, let’s test them out in a real life situation... baking sweets! You are going to follow the exact same recipe twice, but one recipe will have baking soda, and one recipe will have baking powder.


Predict: What differences will your two desserts have? Will changing the baking powder to baking soda even matter? Why do you think this?


The Bake Off
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https://media3.popsugar-assets.com/files/2014/03/03/005/n/1922195/1927bee0c751df2a_chocolate-cake-chocolate-frosting-sq.jpg.xxxlarge_2x.jpg
YOU WILL NEED
* Whatever your recipe of choice calls for


Here’s what to do!

1. Pick your cake recipe (it needs to be from scratch, not using a mix)! You can choose any cake recipe you want, just make sure that the ingredient list calls for baking powder. I’ve included a recipe below, but feel free to pick a different one!

2. After you’re done preparing the first dessert (with baking powder), repeat the same recipe but use baking soda instead.

3. Put both desserts in the oven. Make sure you know which one is which!

4. After the baking time is complete, remove your desserts from the oven. How do they look? Are there any visible differences between the two?

5. After the desserts cool off, cut a piece of each and pick them up. Do they feel different? What are the textures of each like? Does one feel heavier? Fluffier?
​
6. Time for a taste test! Did the change of ingredients affect taste?


Chocolate Coffee Cake Recipe: allrecipes.com/recipe/8014/simple-n-delicious-chocolate-cake/


Extension: If you want to try this the other way around, find a cookie recipe to test out! Cookies usually use baking soda. What do you think would happen if you used baking powder instead?




References
www.ehow.com/about_6470369_baking-baking-powder-reaction-vinegar.html
m.phys.org/news/2014-05-differences-soda-powder.html
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Valentine's Day Science

2/14/2016

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Author: Maddie Van Beek
Picture
http://rlv.zcache.com/geek_nerd_science_happy_valentines_day_postcard-r2a84d261375844f4a2bf5ab8c1a6ad7c_vg8ns_8byvr_1024.jpg


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


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.
Picture
http://cdn.playbuzz.com/cdn/7468087a-4bf9-43c9-8752-2ddab6b954e2/18cfe054-2f4d-4571-a9c4-10ca2585c2d6.jpg

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:
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:
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.
I found that 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
Picture
http://inspirationlaboratories.com/wp-content/uploads/2013/01/candy-heart-ingredients.jpg
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.
Picture
http://f.tqn.com/y/laundry/1/W/a/W/-/-/Borax-Heart-BIG.jpg
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.  Below is an example of white borax:
Picture
https://upload.wikimedia.org/wikipedia/commons/f/f7/Borax_crystals.jpg
Here's a little bit more about borax:
What is borax?
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.


References
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

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Fun with ice!

1/11/2016

2 Comments

 
Author: Maddie Van Beek

Fargo is FREEZING right now, so in honor of the arrival of sub-zero temperatures, we are going to have some fun with ice!


Build your own ice!

Picture
http://videos.videopress.com/x0QczznX/mvi_5168_dvd.original.jpg
Would you believe it if I told you that it’s possible to make ice grow right before your eyes? That’s what you’re doing today! You’ll be cooling down water to the point right before it freezes, then pouring it on ice. When you pour water that cold on ice, it instantly crystallizes and will cause your ice to “grow.” We learned about crystallization in a previous science experiment when we made egg geodes. If you missed it, check it out here: http://discoveryexpress.weebly.com/blog/sedimentation-and-crystallization-how-to-make-egg-geodes


When a substance crystallizes, atoms become tightly packed together and move from a liquid or gas to a solid state. Water crystallizes when it turns into ice. In this experiment, you will see that process happen almost instantaneously! 


YOU WILL NEED:
  • Unopened bottled water
  • Freezer
  • Bowl
  • Ice


Check out this video for a visual example of what we are doing:
Here’s what to do!
  1. Put your unopened water bottles in the freezer. Lay them down horizontally so they are laying on their sides. 
  2. Check your water bottles in 90 minutes to make sure they aren’t frozen. 
  3. Check back every 15 minutes until you can see tiny ice crystals floating around. It usually takes about 2 hours and 45 minutes. 
  4. When you can see ice crystals floating, CAREFULLY remove your water bottles. If you hit the side of the bottle, you may start the crystallization process and your bottle will instantly freeze before your eyes! Although it’s kind of cool to watch, that would put a hold on your activity!
  5. Put an ice cube in a shallow bowl. 
  6. Open your ice-cold water bottle and pour it over your ice cube. Boom! Instant ice! As you pour the water onto the ice, you will see the water instantly crystallize into ice. It appears that the ice cube is growing taller as you pour. See how tall you can build your ice tower! 



Now that you’ve created ice, let’s melt it down! We’ve learned about how salt melts ice in previous science activities, such as when we fished for ice cubes and created our own slushies! Check it out here if you missed it: http://discoveryexpress.weebly.com/blog/how-does-salt-affect-ice


Salt lowers the freezing temperature of water and the melting temperature of ice. Water normally freezes at 32 degrees Fahrenheit, but when salt is added to water, it has to be even colder than that to freeze. In the same way, when salt is added to ice, the ice can melt at colder temperatures than 32 degrees Fahrenheit. This is why it works to sprinkle ice on the roads in the winter! Read this link if you want to learn more about how salt affects ice: http://science.howstuffworks.com/nature/climate-weather/atmospheric/road-salt.htm. 


We are using that same concept today to melt ice, but let’s make it into a fun art project! Grab your camera before you start so you can take some cool pictures of your colored ice at the end. 


Melting ice (in style)
Picture
http://artfulparent.com/wp-content/uploads/2012/07/6a00e55246b63f88340177438e82e0970d-800wi.jpg
YOU WILL NEED:
  • Bowls or containers
  • A large baking pan or tray
  • Salt
  • Food coloring
  • Jars
  • Turkey baster, large spoon, or eye dropper


Here’s what to do!
  1. Pick a few different sizes of containers. You will use these to make your ice. It’s fun to vary your sizes and depths, so pick a variety. 
  2. Pour water in the containers and place them in the freezer where they won’t be disturbed. Let them freeze overnight. 
  3. Remove the containers from the freezer and run a little warm water over the bases to loosen the ice. 
  4. Dump the ice onto the baking pan or tray. This will keep your work area clean!
  5. Now we can really start! Predict: What will happen when salt touches the ice?
  6. Sprinkle salt onto the ice. Make sure not to dump too much! Look closely at the areas of the ice where the salt landed. What happens to the ice? 
  7. You should have noticed that the areas of ice where the salt landed began to melt! If you missed it, sprinkle a little more salt to watch the ice melt. You will notice crevices starting to form. 
  8. Here’s the fun part! Grab your jars and fill them half full with water. Add food coloring to each jar. Use whichever colors you would like!
  9. Use the turkey baster or dropper to suck in your color and squirt it onto the ice. The color will really highlight the areas that melted. Pay attention to how the salt continues to melt the ice as you work. 
  10. Continue to have fun coloring your ice projects and remember to take pictures before they melt away!
  11. To see the areas where your ice is melting even better, take the colored ice outside to look at it in the sunlight!
Picture
http://artfulparent.com/wp-content/uploads/2012/07/6a00e55246b63f8834016768b35337970b-800wi.jpg
Extension: Try using different types of salt! You could use sea salt, table salt, rock salt, etc. to see if certain kinds of salt melt the ice quicker. 


For more fun winter science, check out our snow blog from last year: http://discoveryexpress.weebly.com/blog/winter-is-here-to-stay-make-winter-fun-and-informative-with-a-daily-snow-log


References:
http://www.teachpreschool.org/2014/07/fun-with-frozen-making-ice-grow/
http://artfulparent.com/2012/07/melting-ice-science-experiment-with-salt-liquid-watercolors.html
http://lemonlimeadventures.com/must-try-winter-science-experiments-for-kids/
2 Comments

Happy New Year!

1/4/2016

2 Comments

 
Author: Maddie Van Beek

Happy New Year’s! It’s 2016! Today we are going to do some fun activities to celebrate. But first, check out this New Year’s Science Quiz to see what you know! It’s okay if you don’t know all the answers—there are explanations at the end so you can learn something new for the new year!
New Year Science Quiz
Now that you’ve taken a quick science quiz, it’s time to set some science goals for your year! Have you ever heard of a New Year’s Resolution? Every year, thousands of people around the country make a resolution (goal) to make some sort of positive change in their lives. Most of the time, (88% of the time according to the link below), people fail at keeping their New Year’s resolutions. Why is that?! Too often, people don’t make their goals concrete or reachable, so the resolution quickly seems unattainable. You need to actually train your brain, your prefrontal cortex, specifically, by creating habits in order to achieve your goals. Who knew?!
​
Read the links below to find out why resolutions fail and how to keep yours!
Why do resolutions fail?
How will you keep your New Year's resolution?
Write your goal down, decorate it, and paste it inside your science notebook as a reminder.

Now that you’ve set a science goal for the year, let’s move on to our New Year’s activities!

Fireworks in a Glass

In this activity, you will use oil and water along with food coloring to create a mixture that looks like fireworks in a glass. The science behind this activity is that oil and water DO NOT MIX. Why don’t they mix? They do not mix because water is polar (it has an uneven distribution of electrons in its molecules) and oil is not (it has a very even distribution of electrons in its molecules). Things that are polar usually don't mix well with things that are not polar, like oil (they are not attracted to each other), while things that are polar--like sugar--usually dissolve well in water (the water molecules are attracted to the sugar molecules). Off you need a little more help, check out our earlier blog about solubility:

http://discoveryexpress.weebly.com/blog/what-is-solubility

Watch the video below for a more in-depth explanation of why oil and water don’t mix:
YOU WILL NEED
* Clear glass
* Food coloring
* Vegetable oil
* Water
* Shallow bowl
* Fork

Here’s what to do!
1. Pour a cup of vegetable oil in the shallow bowl.
2. Sprinkle about 12 drops of food coloring in the oil. Use as many different colors as you want! These will be the colors of your “fireworks.”
3. Use a fork to stir the food coloring in with the oil. The food coloring is water-based, so it won’t fully mix in with the oil, but it will break up into smaller blobs.
4. Fill a glass about ¾ full of warm water.
5. Dump the oil/food coloring mixture into the warm water. What happens?
6. The oil stays on top! Remember, oil and water will not mix. The oil is less dense than water, so it floats on top. The food coloring is water-based, so it’s denser than the oil. Eventually, the food coloring blobs will slowly sink through the layer of oil and reach the water. When this happens, the color expands and looks like little colorful explosions!
Picture
http://www.icanteachmychild.com/wp-content/uploads/2012/05/IMG_3391-300x450.jpg
Confetti Eruption

In this activity, you will see baking soda and vinegar react, much like when we did exploding glow in the dark art (http://discoveryexpress.weebly.com/blog/exploding-glow-in-the-dark-art).

Baking soda (a base) and vinegar (an acid) create an acid-base reaction. When this reaction occurs, carbon dioxide gas is released in the form of foamy bubbles. For a full explanation of why these two substances react together, check out this link:

http://scienceline.ucsb.edu/getkey.php?key=4147

YOU WILL NEED
* Baking soda
* Vinegar
* Plastic party cups (or any glass)
* Confetti or glitter
* Food coloring (optional)
* Bowl
* Turkey baster or eye dropper


Here’s what to do!
1. Fill a small bowl with about two cups of baking soda. The amount doesn’t really matter, but two cups is enough for plenty of foamy fun!
2. Add a few spoonfuls of confetti or glitter to your baking soda.
3. Add a tablespoon of water to your baking soda and mix it in. Continue to do this until you have a dough-like consistency. This more evenly distributes the confetti and makes the mixture easier to scoop into the glasses.
4. Place the party glasses in a baking pan to contain the mess. This will make cleanup easier.
5. Scoop about ¼ cup of the mixture into each party glass.
6. Pour a cup of vinegar into a separate glass and add a few drops of food coloring if you want your eruptions to be colored!
7. Use the turkey baster or eye dropper to suck in the vinegar.
8. Squeeze the vinegar into the party glass. TADA! You should see a colorful, glittery eruption! Repeat as often as you want to create more foamy fun. As the foam fizzles out, just add more baking soda or more vinegar.
Picture
http://littlebinsforlittlehands.com/wp-content/uploads/2015/12/New-Years-Eve-Science-Baking-Soda-Eruptions-680x1020.jpg
References:

​http://www.icanteachmychild.com/fireworks-in-a-jar/
http://littlebinsforlittlehands.com/confetti-science-eruptions-new-years-eve-science-activity/
2 Comments

Science of Starch

11/29/2015

2 Comments

 
Author: Maddie Van Beek

Happy Thanksgiving! Just a few days ago, most of the country was celebrating 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! ​
Picture
http://foodnetwork.sndimg.com/content/dam/images/food/fullset/2011/8/10/1/Thanksgiving-2011_IG1A02-homemade-gravy_s4x3.jpg
(For more information about Thanksgiving, it’s history, and the science around it, check out our Thanksgiving blog from last year: http://discoveryexpress.weebly.com/blog/happy-thanksgiving)

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. 

​
How does starch work? http://www.thekitchn.com/food-science-how-starch-thicke-83665
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. 


Picture
http://hyperphysics.phy-astr.gsu.edu/hbase/organic/imgorg/starch.gif
To learn even more about the science of starch, check out this link: http://www.scienceinschool.org/2010/issue14/starch


Try to 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. 


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
2 Comments

Elephant Toothpaste

11/22/2015

2 Comments

 
Author: Maddie Van Beek

Today, we are going to create a fun and foamy reaction that looks like a tube of toothpaste big enough for an elephant! You've created other reactions in the past, such as when we exploded a plastic bag or created film canister rockets. The most similar reaction to the one we are creating today is when we blew up a balloon with yeast. Yeast is going to be part of our reaction today. ​
Picture
https://www.questacon.edu.au/sites/default/files/assets/outreach/program/sqsc/assets/images/elephants_toothpaste_930w.jpg
If you missed our other ultra-reactive blogs, check them out here: ​
Acid / Base Reactions
Film Canister Rocket
Yeast as a Catalyst
What are chemical reactions? In a chemical reaction, two or more molecules interact, which causes a change in the molecules. Old bonds are broken and new ones are formed. 


Learn more about chemical reactions here: http://www.chem4kids.com/files/react_intro.html


There are more than one type of chemical reaction. An exothermic reaction releases heat or light. An example of this is wood burning in a fire. The wood burning releases heat and light. This is the opposite of an endothermic reaction. While an exothermic reaction releases energy, an endothermic reaction absorbs it. Today, you are going to be creating an exothermic reaction.


In order to create Elephant Toothpaste, you will use a catalyst to get the reaction going. A catalyst increases the rate of a chemical reaction. ​
Picture
http://www.theneighborhoodmoms.com/wp-content/uploads/2015/04/yeast.jpg
In this activity, yeast is your catalyst. When the yeast meets the hydrogen peroxide, it will cause the peroxide to quickly release oxygen.  ​
Picture
http://www.middleschoolchemistry.com/img/content/multimedia/chapter_6/lesson_5/hydrogen_peroxide_decomposition.jpg
The oxygen is released in the form of a bunch of tiny bubbles, thus creating foam that looks like toothpaste!
Vocab to remember:
  • Reaction
  • Exothermic 
  • Endothermic
  • Catalyst


Check out this amped-up version of Elephant's Toothpaste on Jimmy Kimmel. ​
Our reaction won't be THAT crazy, so don't worry! Let's get started on making our own Elephant's Toothpaste!


YOU WILL NEED:
  • Pan or tray
  • Empty 16 oz plastic bottle
  • 20-volume hydrogen peroxide (6% solution) : This can be purchased from a beauty supply store
  • One packet (one tablespoon) of dry yeast
  • Water
  • Liquid dish washing soap (like Dawn)
  • Small cup
  • Safety goggles 
  • Food coloring (optional)




Here's what to do!
  1. PUT YOUR SAFETY GOGGLES ON! Hydrogen peroxide can irritate your eyes, so let’s be careful! Ask an adult for help when you handle the hydrogen peroxide. 
  2. Place your empty 16 oz bottle in the middle of your tray or pan. 
  3. Carefully pour 1/2 cup of hydrogen peroxide into the plastic bottle.
  4. If you want your “toothpaste” to be colored, add a few drops of food coloring into the plastic bottle. 
  5. Measure out one tablespoon of liquid dish washing soap and dump it into the plastic bottle. Swish the bottle around to mix the soap in with the hydrogen peroxide. Set the bottle aside. 
  6. Pour 3 tablespoons of warm water into the small cup. 
  7. Add 1 tablespoon of yeast into the warm water and mix it in for about 30 seconds. 
  8. Here’s the fun part! Pour the yeast liquid into the plastic bottle and stand back! 
  9. FOAM FOUNTAIN MANIA! Feel the bottle. It should be warm. Remember, this is an exothermic reaction, so it produces heat. After the initial foam shoots out of the bottle, it will continue to ooze out like toothpaste for a while. 
  10. After the foam subsides, try it out again. This time, decide how you can make this activity an experiment. Choose a variable: You could alter the amount of yeast, the amount of hydrogen peroxide, or even the temperature of the water. Remember to only alter one variable at a time and make sure to record your observations!


References
  • https://sciencebob.com/fantastic-foamy-fountain/
  • http://www.stevespanglerscience.com/lab/experiments/elephants-toothpaste/
  • https://en.wikipedia.org/wiki/Exothermic_reaction
  • https://en.wikipedia.org/wiki/Endothermic_process
2 Comments

Iodine Clock Reaction

11/16/2015

0 Comments

 
Author: Maddie Van Beek

Picture
https://www.chem.wisc.edu/deptfiles/genchem/demonstrations/Images/12kinetic/clock.jpg
Today, we are going to mix together a few different substances to create a new substance of a different color! I know this sounds like common sense... when you mix together certain colors, they create a new color. For example, if I mixed together a red liquid and a yellow liquid, the result would be an orange liquid. But today is a little different! We are going to mix together a few substances–different substances that will cause a clear liquid to suddenly change blue! Don’t believe it’s possible? Let’s get going!


Before we move on to the activity, you must understand the reaction that will occur. The reason that your liquid will turn from clear to blue is because the substances involved cause a chemical reaction. That reaction makes all the difference! Otherwise, there would be NO WAY that two clear liquids would make blue! (For a review of chemical reactions, visit our blog about the reaction between vinegar and baking soda).



The reaction that we are working with today is called an Iodine Clock Reaction. You will be using iodine, starch, and Vitamin C to create this reaction. The starch is trying to turn the iodine blue, but the Vitamin C is battling the starch. This causes a delay in the reaction. Eventually, the starch defeats the Vitamin C and the color change occurs.

The delay is the reason it’s called a clock reaction. Initially, when the two liquids are mixed, nothing happens. It takes a certain amount of time for the reaction to occur, and then BAM! Your liquid will suddenly change colors!


Check out this video of the reaction that you will be creating:

YOU WILL NEED:
* Iodine tincture (2% from the pharmacy)
* Vitamin C tablet (1000 mg)
* Hydrogen peroxide (3% from the pharmacy)
* Liquid laundry starch
* 3 clear plastic cups
* Measuring spoons and measuring cups


Here’s what to do!
1. Label your cups A, B, and C.
2. Put a 1000mg Vitamin C tablet into a plastic bag and crush it up. You could use any hard object to help you crush it into a fine powder.
3. Carefully dump your Vitamin C powder into cup A. Add 2 ounces of warm water into the cup and stir until the powder is dissolved. Observe: What color is liquid A? What does it look like?
4. Before the next step, take a look at the iodine. What color is it?
5. Put one tablespoon of liquid A into the cup labeled B. Add one teaspoon of iodine. What happens to the color when these two liquids are mixed together? Set cup A aside.
6. Put 2 ounces of warm water into the cup labeled C. Add one tablespoon of hydrogen peroxide, then add 1/2 teaspoon of liquid starch. Use a spoon to stir the liquids together.
7. Now, let’s get going with this chemical reaction! Carefully pour the liquid in cup B into cup C. Pour the liquid back and forth between the two cups a few times and then wait patiently for a chemical color-changing surprise!


Extension: You just demonstrated an iodine clock reaction. How can you add a variable to create an experiment? Try changing the temperature of the water or the amount of Vitamin C or iodine to see if this affects the time it takes for the liquid to change colors! What about mixing? If you just let the liquid sit after you mix them, does it take longer to change? If you stir it more, does it change faster? Make sure to record your observations!


References:
https://en.wikipedia.org/wiki/Iodine_clock_reaction
https://sciencebob.com/rapid-color-changing-chemistry/

0 Comments

Halloween Science

11/1/2015

0 Comments

 
Author: Maddie Van Beek

Halloween may be over, but that doesn’t mean you can’t still have some spooky fun with Halloween science activities! 


1. Use your colorful candy to try out candy chromatography! 


What exactly is chromatography? 


Chroma means color and graphein means to write. 


There are a few different kinds of chromatography, but today you are going to be dealing with paper chromatography. When you use paper chromatography, you can separate different inks or dyes into their individual components. For example, a black marker actually has many different colors of dye to create black ink.

​Watch the video below to watch how paper chromatography can be used to separate black ink into its individual colors: 

You can use this same idea to separate the dyes of your favorite candies! 


YOU WILL NEED
  • M&Ms or Skittles
  • Coffee filter paper
  • A tall glass 
  • Water 
  • Table salt 
  • Pencil
  • Scissors
  • Ruler 
  • 6 toothpicks 
  • Aluminum foil 
  • 2 liter bottle with cap


Check out our blog about candy chromatography here for instructions: http://discoveryexpress.weebly.com/blog/candy-chromatography


2. Create your own glowing beverages! 


Did you know that tonic water glows under a black light? The reason that it does this is because of one special ingredient: quinine. 


Why is quinine fluorescent? Read the link below to find out! 
Why is quinine fluorescent?
Now that you know about quinine, do you know what a black light is? Why is a black light any different from a regular light? They might appear the same as any other light bulb, but they function very differently. Black lights actually produce ultraviolet light. When you turn a black light on, it causes white things to glow in the dark. 


Read about black lights in the link below to find out how they work: ​
How do black lights work?
YOU WILL NEED
  • Tonic water
  • Ice cube trays
  • Sprite or 7-up
  • A black light

​
Here’s what to do! 


The instructions for this activity are very simple. Make ice cubes out of tonic water and then put them in any light colored drink such as 7-up or Sprite. Turn on a black light, turn off the lights, and watch your beverages glow an eery blue!


3. Make pumpkin slime!


The slime that you will be creating is a non-newtonian fluid. Newtonian fluids behave as you would expect a liquid to behave. For example, when you hit water, it gives way. You can easily put your hand through it without much resistance. Non-newtonian fluids sometimes act like a solid and sometimes act like a liquid. When you hit a non-newtonian fluid, it resists the impact. How can that be? 


Watch this video to see people experiment with non-newtonian fluid. They even try to bike across it! You’ll be amazed at its power to resist stress. ​
YOU WILL NEED:
  • One pumpkin
  • Cornstarch 
  • Mixing bowl
  • Spoon
  • Cookie sheet or pan
  • Food coloring (optional: your pumpkin will already color your slime an orangey tint)
Check out our blog from a few weeks ago to learn more about non-newtonian fluids and create your own pumpkin slime: http://discoveryexpress.weebly.com/blog/pumpkin-slime




References:
https://sciencebob.com/free-halloween-science-ideas/


http://www.scientificamerican.com/article/shining-science-explore-glow-in-the-dark-water/


http://science.howstuffworks.com/innovation/everyday-innovations/black-light.htm
0 Comments
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