Cozee’s Comfort Science

By definition, heat is the transfer of kinetic energy from one object to another. The more kinetic energy something has, the warmer it is. This simple experiment can demonstrate how temperature affects the movement of molecules.

What You'll Need:

• 3 clear cups or jars
• Water
• Food Coloring
• Masking Tape
• Markers

The Experiment:

1. Use masking tape and markers to label the jars. Label one "Hot," one "Cold," and one "Room Temperature."
2. Fill each jar with the correct temperature water. It's a good idea to let an adult fill up the "Hot" jar!
3. Place a drop of food coloring into each jar and watch what happens.

The Science:

What happened to the food coloring? As you'll see, the food coloring in each jar will spread through the water faster or slower depending on the temperature of the water. It will spread fastest through the hot water because the molecules are moving faster; likewise, it will take the longest to spread through the cold as those molecules are moving much more slowly.

Conduction of heat is a fundamental part of how heating and cooling systems work. What materials conduct heat? This experiment will let you test a few to find out.

WARNING: This experiment involves boiling water. You must get an adult to help you! Safety first!

What You'll Need:

• A pot or microwave safe container
• Water
• 3 shallow glass bowls
• 3 spoons - one metal, one wood, one plastic
• 3 small pats of butter

The Experiment:

1. Place one spoon into each of the three bowls so that the handle of the spoon is touching the bottom of the bowl and the scoop of the spoon is resting on the edge.
2. Carefully heat enough water to fill each bowl halfway up until it's boiling, either using a pot on the stove or the microwave.
3. Again, very carefully, poor the boiling water into each bowl, filling it about halfway.
4. Place 1 pat of butter onto the scoop of each spoon and observe for 5 minutes.

The Science:

You should see each pat of butter melting at a different rate. Which one was fastest? Which one was slowest? The butter in the metal spoon will melt the fastest because metal is an excellent conductor of heat - so it's transferring heat from the boiling water into the butter, causing it to melt quickly. Of the three, plastic is the poorest conductor of heat (plastic will often melt rather than conduct when exposed to heat), so that butter will melt more slowly. The butter in the wooden spoon should fall somewhere right in the middle, as wood will conduct some heat, but very inefficiently.

This fun experiment shows how heat can change the pressure in a closed container.

WARNING: This experiment involves a candle flame. You must get an adult to help you! Safety first!

What You'll Need:

• A shallow bowl or dish
• 1 candle
• Water
• Food coloring
• A lighter (utility lighters work best for safety)
• 1 large glass jar

The Experiment:

1. Place the candle in the middle of the dish.
2. Put a few drops of food coloring in your water, then poor it into the dish around the candle.
3. Use the utility lighter to light the candle.
4. Place the glass jar over the candle so the mouth rests in the water.
5. Observe for a few minutes and see what happens.

The Science:

As the candle flame burns through the oxygen inside the jar, it creates an area of lower pressure - similar to a vacuum. Outside the jar is normal atmospheric pressure, so it starts pushing on the water while the lower pressure area inside the jar pulls on it. That makes the water rise up around the candle to fill the jar. Amazing, huh?