Kids & Family

At Home Experiments

Coffee Fossils

Materials

• 1 cup each of flour and coffee grounds (used or unused)
• 1/2 cup each of salt and water
• shells, pasta or other items to make impressions.

Method

1. Combine coffee, flour, salt and water in a bowl. (Add water slowly.)
2. Stir and mix well.
3. Shape the mixture into “patties”.
4. Use shells or other materials to make an imprint, or use pieces of pasta to represent the bones of a dinosaur.
5. Allow them to dry overnight.

The Science

The word Fossil comes from the Latin fossils meaning ‘dug up’. They are defined as the remains or traces of plants or animals that lived a long time ago. Fossils are usually preserved in sedimentary rocks such as sandstones, shale or limestone.

Challenge

How are fossils formed? What common types of plants and animals are found as fossils?

Amazing Polymers

Materials

• Zipper type bag (sandwich size)
• water
• sharpened pencil.

Method

1. Fill the zipper type bag 2/3rd full with water and seal the bag.
2. Carefully, yet firmly and quickly, poke a sharpened pencil all the way through the bag so it protrudes from both sides of the bag.

The Science

Plastic bags are made of long chains of polymers (picture a bowl of cooked spaghetti before you add sauce). When you poke the pencil in the bag you are moving those strands a part. The elasticity of the bag pushes the strands back along the sides of the pencil, sealing the bag and keeping the water inside. When the pencil is removed, the strands will not completely return to their original position and the water will flow out of the holes.

Challenge

Ask the students to predict what will happen before you stick the pencil into the bag. What if you used different brands or sizes of zipper type bags? Different types of pencils? Different volumes of water?

Hoop Gliders

Materials

2 strips of paper (cut one strip 1 inch wide and 5 inches long, cut the second strip 1 inch wide and 10 inches long), ruler, scissor, pencil, non-bendable, plastic drinking straw, tape

Method

Curl the paper strip into a hoop, taping the ends together. Tape the small hoop to one end of the straw, and the big hoop to the other end, making sure they are lined up together. Hold your Hoop Glider in the middle of the straw, with the small hoop in front and throw it gently like a paper airplane.

The Science

If you throw a plain straw, it doesn’t go very far. But when you add paper hoops, the straw glides through the air. That’s because the hoops act like wings. Things that fly—like insects, birds, and airplanes—all have wings.

Challenge

Try changing the size of the hoops on your glider. How does it fly with different sized hoops? Why?

Making Music

Materials

• 5 or more drinking glasses or glass bottles
• Water
• Wooden stick or pencil

Method

1. Line the glasses up next to each other and fill them with different amounts of water. The first should have just a little water and the last should be almost full. Each glass in between, should have slightly more than the last.
2. Gently tap the first glass (with the least amount of water) and observe the sound. Next, gently tap the glass with the most water. Do they sound the same?
3. Tap the other glasses to hear the tone differences. Can you tap out a tune?

The Science

Each of the glasses will have a different tone when tapped with the pencil. The glass with the most water will have the lowest tone while the glass with the least amount of water will have the highest. Small vibrations are made when you hit the glass and this creates sound waves, which travel through the water. More water means slower vibrations and a deeper tone.

Challenge

Does the temperature of the water make a difference in the sound? What happens if you use a spoon instead of a stick or pencil? REMEMBER to tap gently!

Don’t Spill the Water

Materials

• A glass filled to the top with water
• A playing card, note card, or smooth piece of cardboard

Instructions

1. Place the card over the mouth of the glass and hold it firmly.
2. Quickly turn the glass upside down, over a bowl or the sink.
3. Carefully let go of the card without moving it.

The Science

If you look at the top of the glass of water (which was the bottom), you’ll notice a small area of air. Because the rest of the glass is full of water, there’s no chance for more air to get into that area. This air represents an area of low pressure. There are more air molecules pushing up against the bottom of the note card, creating a higher pressure area, compared with the lower pressure area inside the top of the glass. The force from the atmospheric pressure outside holds the card up and the low pressure area in the glass, prevents the water from pushing the card down.
Water’s adhesion property also plays a role in this experiment. Adhesion occurs because water molecules are attracted to or stick to other materials. In this experiment, the water molecules are attracted to the paper, adhering to it, keeping the note card in place.

Challenge

What if the glass is half full of water? What about one-fourth full? Does it work if you use a carbonated beverage instead of water?