Water that you find in nature is not necessarily clean or pure; you would not want to drink pond water, for example. There are ways to clean water, though, and you can try this experiment at home!
First, take a clean jar with a lid and fill it with water from a lake, pond, stream, or any other source of water outside your home. Put the lid on until it is time for the next step. What do you notice about the water?
To clean the water, you will need something called alum. Alum is a hydrated double sulfate of aluminum and potassium, used in dyeing and tanning. If you don’t have this at home, it can be found in the spice aisle in the grocery store.
Put 2 tablespoons of alum in your water, close the lid tightly, and shake it up. Then let the water sit for a few hours.
When you look at your jar again, what do you see?
You may notice that the dirt gets pulled to the bottom. In a real water treatment plant, the added alum forms clumps with the dirt and pulls it down to the bottom of the basin.
To learn more about water and water pollution, check out one of these books.
Did you know that salt lowers the temperature of ice water? To see this process happen, try making ice cream with only a few ingredients.
1 Gallon Zip Bag
2 Sandwich Zip Bags
1/3 Cup Rock Salt
1/2 Cup Whole Milk
1 Tablespoon Sugar
1/2 Teaspoon Vanilla Extract
Ice (enough to fill 1/2 of the gallon zip bag)
In one sandwich zip bag, combine the milk, sugar, and vanilla extract together. Then, zip the bag close.
Put the zipped bag with the mixture in the second sandwich zip bag and zip this one closed. This gives your mixture extra protection.
In the gallon zipped bag, make sure there is enough ice to fill 1/2 of the bag. Then, add the rock salt to the ice.
Place your sandwich zip bags with the mixture into the gallon zip bag of ice and salt. The, zip the gallon zip bag close.
Put on your gloves and shake your gallon zip bag for 10 minutes.
After 10 minutes, take you sandwich bags out and open them to tasty vanilla ice cream.
There are many different recipes to make ice cream like this on the internet. We found this one on the Happy Toddler Blog.
Lift Ice Cubes with Chemistry
After making your tasty treat, learn more about salt and ice including why it is used on snowy roads in the winter. You can even learn how to make a piece of yarn to stick to ice with this experiment from Scientific American.
How do insects survive the long, cold winter? In several different ways!
Some Overwinter as Eggs
Praying mantids spend the winter as eggs, waiting for the warmer spring temperatures to hatch. Both the native Carolina Praying Mantis and the Chinese Praying mantis are found in Illinois.
Some Overwinter as Larvae
Woolly bear caterpillars, the larval form of the Isabella Tiger Moth, spend the winter curled up under leaves.
Some Overwinter as Nymphs
Insects that have an incomplete metamorphosis only have three stages of life: egg, nymph and adult. Dragonflies spend the winter as nymphs underwater will stay active under the ice. They emerge in spring as adults.
Some Overwinter as Pupae
Some moths and butterflies will stay in their pupal cases (chrysalides or cocoons) and come out in the spring as adults.
Some Overwinter as Adults
Monarch butterflies migrate to Mexico in the fall and wait for the spring to arrive to begin their journey back home.