Allow students to see how water is capable of being a solid, a liquid or a gas. Fill a clear jug with water and ask the children to tell you what they see inside the jug. Explain to them that the water inside the jug is a liquid and that this is likely the form of water they see most often. Ask them if they think there is any other way that they can see water. Pour some of the water into a pot and place some of the water into a small bowl. Set the pot on a stove or hot plate and turn the heat up to high. Place the bowl in the freezer. Ask the students to predict what will happen to the water in each situation. As the water boils and freezes, explain why and how water turns to vapor or freezes.
Use water to teach the process of capillary action. Fill a glass with water and set it next to an empty glass. Ask the students if they think there is any way they can get water into the empty cup without pouring it out of the full cup. Twist several paper towels together into something that looks like a rope. Place one end of the paper towels into the full glass and one end into the empty glass. After a few minutes, the water will transfer to the empty glass until both glasses contain an equal amount of water. Explain how capillary action is similar to transferring the water.
Explain the process of diffusion with this water science experiment. Fill a clear glass with water and place a drop of food coloring in it. Do not mix, stir or shake the water--just watch what happens as the food coloring travels through the water. The food coloring eventually moves throughout the water, changing the color. Explain how this is the process of diffusion, or the process of two liquids mixing.
Investigate whether sound travels better through air or water. Fill a glass jug with water. Tap a spoon on a hard surface and hold it in the air. Ask the students if they can hear the sound that the spoon is making. Show them the glass jug and ask them if they think they will be better able to hear the sound the spoon is making through the water. Tap the spoon again and suspend it in the water. Have the students press their ears to the jug and ask them what they hear (the sound of the spoon vibrating). Explain how sound waves travel through water much quicker than they travel through air.