States of Matter: In order to demonstrate the difference between the states of matter in solids, liquids and gases students used marshmallows. The solids were placed close together, the liquids were a bit spread apart and the gases were placed far apart.
Types of Clouds: We did a similar project to show the difference between types of clouds. We used cotton balls on black construction paper.
Sound Travels: Students learned that sound travels faster through a solid than through the air. A hanger was tied to a string and hit against a desk. The students heard the sound. To compare, the students then placed each end of the string to their ears and hit the hanger against the desk again. The sound was louder traveling directly through the string than through the air. We also demonstrated this by making paper cup telephones. Speaking in a whisper with no "telephone" was not as loud as whispering through the "telephone."
Sound Waves: Understanding sound waves is a challenge for students. It is an abstract concept. Using a bowl of water and tuning forks makes this concept more tangible for students. Place the tuning fork in a bowl of water and strike it. This creates ripples in the water, much like sound waves. As the students hear the vibrations, they can also see the sound waves.
Blubber Keeps Whales Warm: The ocean is icy cold. It is difficult for students to understand how whales stay warm in the ocean. Have students place their hands in ice cold water and see how long it takes for them to feel the cold (it will only take a second!). Then, have students place their hand into the "blubber bag" (fill a ziploc bag with crisco and place a second bag inside so the students' hands do not get sticky). Then they can place their hand back in the ice water. Their hand will not feel the cold water with blubber protecting them.