Last year at Thanksgiving, we looked at an experiment that lets you determine the amount of energy released through the burning of food by measuring the change in temperature of a sample of water from the combustion of a small amount of food. This year, we’re focusing on the food: Check out these four Thanksgiving-themed experiments that you and your students or your kids can easily try in the classroom or at home to get extra excited for the extra calories you’ll enjoy next Thursday.
Ingredients: vinegar, water, various sizes of turkey (or chicken) bones
Supplies: bowls
Steps:
Pour vinegar into one bowl and water into another
Place bones of various sizes into each bowl.
Cover the bowls with a lid or plastic wrap.
Leave the bones alone for at least 48 hours.
Remove the bones from the bowls and rinse them in warm water.
See if you are able to bend the bones. If not, try placing them back in the vinegar for another 24 hours.
Bones are mostly made up of calcium phosphate and collagen. Calcium phosphate is very hard, while collagen is very tough, yet flexible. The combination makes bones very strong. Vinegar is a dilute form of acetic acid, which will dissolve the calcium phosphate. All that’s left behind is the collagen, giving you a flexible bone. See you if you can tie one in a knot!
Ingredients: sweet potato or white potato, water
Supplies: glass jar, toothpicks, clear paper cup
Steps for growing a white potato:
Stick four toothpicks into the sides of the white potato, arranging them so they stick out all around the middle.
Insert the wide end of the potato into the clear plastic cup so the toothpicks rest on the rim of the cup.
Add enough water to the cup to cover just the bottom of the potato.
Place the cup with the water and potato in a dark, cool place.
After one to two weeks once the eyes and sprouts have had a chance to grow, put the white potato in the cup near a sunny window. Allow the potato to continue growing, adding water when needed, or transplant to soil.
Steps for growing a sweet potato:
Stick three to four toothpicks into the bottom of the sweet potato, like chair legs.
Insert the sweet potato into the glass jar, where the toothpicks will hold the potato a few inches away from the bottom of the jar.
Add enough water to the jar so the bottom of the potato sits fully in the water.
Place the jar in the window sill or a place where it will get lots of sunshine.
Check the jar daily, adding water when needed to keep the potato bottom wet. Once a week, pour all of the water out and refill it with fresh water, covering the bottom of the potato. A few days after you see the first leaves, you will see vines growing. After two to three weeks, you will have several long vines with green leaves. You can continue watering your sweet potato as usual in the jar or transplant it into a pot with soil.
You can transplant your sweet or white potato by placing it into a pot large enough for you to bury the potato in soil. Cover the potato with potting soil, patting the soil around the potato. Keep the leaves away from the soil so they can continue to grow. Water the soil when it begins to get dry to the touch.
Suggestions for more science: Grow both a white potato and a sweet potato at the same time to compare the similarities and differences in how they grow. Or, try growing an avocado plant exactly the same way by submerging the bottom of the avocado pit in water using toothpicks.
Ingredients: cranberry juice, lemon juice, baking soda
Supplies: clear cups, spoons
Steps:
Fill the cup halfway up with cranberry juice. Add a spoonful of baking soda and stir (check out that fizz!).
Watch the cranberry juice change color. What does it look like now? Why do you think this happened? What would you need to do to change it back?
Add a little bit of citric acid or lemon/lime juice to the cup (it'll fizz again!). The juice should start changing color. Add a little more acid if the change isn’t obvious.
When you add the baking soda base, you neutralize the acid in the juice, so the anthocyanins (natural pigments found in many brightly colored foods) change color. When you add the acidic lemon juice, the anthocyanins turn back to red. You can get other colors out of your cranberry juice by using different acids and bases.
Suggestions for more science: Use vinegar, cola, or baking powder in the place of baking soda. What colors do you see? We know that the change in color is a result of whether what you add to the cranberry juice is an acid or a base. Guess which substance is which, and test your theory using pH test strips. Were you right?
Now that you understand the basics of acids versus bases, take your knowledge one step further by exploring acids, bases, and the pH scale with other hands-on experiments with this all-in-one kit.
Ingredients: heavy whipping cream
Supplies: glassware with lid (e.g., mason jar)
Steps:
Fill your glass jar about halfway with cream.
Make sure the lid of the jar is tight and shake. Note: Making butter requires a bit of arm strength, so you think about trading off with your kids or students.
Check your glassware every 5 minutes to see the changes. After the first 5 minutes, there may be no real visible change. At the 10-minute check-in mark, see if you notice what looks like whipped cream. After another couple of minutes, you may observe that you can’t detect the liquid inside very well.
After a few more minutes (and we mean a few—maybe as many as 15 more)
Heavy cream has a lot of fat in it. When the cream is shaken, the fat molecules begin to separate from the liquid. The more the cream is shaken the more these fat molecules clump together, forming a solid, which is butter. The liquid that’s left after the solid has formed is called buttermilk.
