Lava Lamp: The students observed that when you mix oil and water together they separate from each other. The oil ended up on top because it has a lower density than the water. We then added food coloring and watched it fall through the oil and mix with the water at the bottom. We then added tiny pieces of Alka-Seltzer which created small bubbles of carbon dioxide gas that would rise to the top. The gas would then escape when it reached the top and the colored water would fall back down. The students learned the reason the Alka-Seltzer fizzed in such a way is because it contains citric acid and baking soda and the two react with water to form sodium citrate and carbon dioxide gas.
Traveling Water: The students learned that water has a lot of molecules that are held together by electrical molecular bonds. So we took a glass of water with a piece of string and and dumped the water along the string and into the empty glass. Because water has such strong hydrogen bonds it allowed the water molecules to stick together and travel down the string and into the empty cup.
Dissolving Sugar: We dissolved sugar in both cold and hot water. The students were able to observe that the cold water wasn’t able to dissolve as much sugar as the hot water. The reason the hot water dissolved more sugar is because it has faster moving molecules which are spread further apart than the molecules in the cold water. So with bigger gaps between the molecules in the hot water, more sugar molecules can fit in between.