Ice Cream in a Baggie
½ cup milk
½ teaspoon vanilla
1 tablespoon sugar
4-5 cups of ice
4 tablespoons of salt (1/4 cup)
2 quart size Zip-loc Bags
1 gallon size Zip-loc Bag
Mix the milk, vanilla, and sugar together in one of the quart size bags. Seal tightly
(grown ups should check the bags for young children), allowing as little air to
remain in the bag as possible. Put the bag with the mixture in it into a second quart
sized bag. Also allow as little air in this bag as possible. Too much air left inside
may force the bag open during shaking.
Fill the gallon-sized Zip-loc bag with ice and salt and put the smaller bag of milk
mixture inside. Again, let all the air escape and seal the bag.
Shake and massage the bag, allowing all the ice to surround the cream mixture. Five
to eight minutes is adequate time for the mixture to freeze into ice cream.
Want to extend this experiment?
*Explore the difference in using crushed or cubed ice
*Try using different amounts of ice and salt. Will more salt make it go faster or will
it not make a difference?
*Time how long it takes for the ice cream to freeze
What does the salt do?
Just like we use salt on icy roads in the winter, salt mixed with ice in this case also
causes the ice to melt. When salt comes into contact with ice, the freezing point of
the ice is lowered. Water will normally freeze at 32 degrees F. A 10% salt solution
freezes at 20 degrees F and a 20% salt solution freezes at 2 degrees F. By lowering
the temperature at which ice is frozen, we are able to create an environment at
which the milk mixture can freeze at a temperature below 32 degrees F into ice
cream.
Gak
½ cup of glue
2-4 drops of food coloring
A few tablespoons of Liquid Starch (try Linit-Brand Liquid Starch)
Plastic Cup
Spoon
Sandwich Sized Zip-loc Bag
Drop food coloring into your cup of glue. Mix it with a spoon until your glue is no
longer white and it is the color you would like it to be.
Add small spoonfuls of liquid starch. Stir after each spoonful is added.
When your mixture looks like you can touch it without your hand getting covered in
glue, take it out of the cup and play with it. If it feels a little sticky, add a drop of the
liquid starch to your gak and mix it in with your hands.
Oobleck
1 cup water
1 ½ - 2 cups corn starch
A few drops of food coloring of your choice
Mix food coloring and water together. Mix the water with the corn starch. Just mix a
little water at a time. You may not need the whole cup!
Your oobleck will be ready when the consistency is that of a thick liquid, which can
also feel like a solid!