Pollution Catchers

Create pollution catchers to observe and compare the air in different locations.
To make the pollution catchers:
Take 4 index cards and create a hanging loop out of string and tape for each one. Smear the unlined side of each index card with a thin layer of petroleum jelly. Hang 3 of the cards in various locations. Put the 4th inside a plastic zip-top bag as a control. After 2 days, put each index card into a zip-top bag and compare what is on them using a magnifying glass.

Soggy Popcorn

Q: How does the amount of moisture affect the size and volume of popcorn?

Procedure:
1. Put 2 cup of yellow popcorn kernels into each of 2 glass jars with lids. Label one "A" and one "B".
2. Close the lid tightly on "A".
3. Add 1/8 cup of water to "B" and close the lid tightly.
4. Put 1 cup of popcorn on a paper towel and spread them around in an even layer. This is sample "C".
5. Leave all the samples in a cool, dry place for 7 days. Turn the glass jars once a day and record any visible changes.
6. Pop all samples 1/2 cup at a time. With each batch, measure the total volume. Measure 10 popped kernels and calculate the average size. Rate the batch as small- less than 1/2 inch, medium-1/2-3/4 inch, or large-more than 3/4 inch.
Compare.

Other ideas: compare different types of popcorn, or popcorn stored in other locations such as the refrigerator or freezer.

Flower Power

Q: How do different additives affect the freshness of flowers?

Control: a flower in plain water.
Experimental conditions (2 liters each):

• Commercial preservative
• 1/2 teaspoon bleach, 3 Tablespoons sugar, and 4 teaspoons vinegar
• half a liter of lemon-lime soda and 1/2 teaspoon bleach, add 1/4 teaspoon bleach every 4 days
• 1/4 cup mouthwash
• a penny and one aspirin tablet

Hot Cocoa, Anyone?

Experiment with temperature of liquids using cocoa.
Try making cocoa in different cups and see how it affects the cooling rate.
Try mixing half boiling water and half cold water and see how it affects the temperature.

Popcorn Fever

Q: How does the temperature at which you store microwavable popcorn affect how well it pops?

Materials:
10 bags microwave popcorn

Label 3 bags "refrigerator", 3 bags "counter", and 3 bags "freezer". Leave one bag unlabeled. Put the bags in their spots (leave the unlabeled bag on the counter). Wait 24 hours.
Microwave 1 cup of water for 1 minute to preheat the microwave.
Put the unmarked bag in the microwave and pop it until the rate slows to 2-3 seconds between pops. Stop the microwave and note how long the popcorn was in there.
Take 1 bag out of the freezer and microwave it for the time noted above. Take the bag out of the microwave, measure the popcorn and record the volume. Pour the popcorn onto a cookie sheet and count the number of unpopped kernels. Repeat these steps for the rest of the popcorn.
Average the results for each group and compare.

Notes: Popcorn pops because of the starch and moisture inside the kernel, and the hard shell surrounding the kernel. When the moisture inside expands, the popcorn pops.
When heated, the starch expands, forming thin, jelly-like bubbles. The starch bubbles fuse together with the ones around them, creating popcorn.

From: Prize-Winning Science Fair Projects for Curious Kids by Rhatigan & Newcomb

The Way the Ball Bounces

Q: How does the height from which you drop a ball affect how high it bounces?

Attach 2 yardsticks to a wall and drop a ball from varying heights to see how high it will bounce.
Graph to compare. Also try the experiment with different balls or different flooring materials.

Notes:
Discuss the difference between potential and kinetic energy.