H₂Ohhh! Other Experiments

Materials

• Eyedroppers, several per table
• Pennies, 1 per child
• Bowl of water, 1 per table
• Cup with one inch of water in it, 1 per child
• Paper towels, 1 per child
• Printer paper, 1 per child
• Dark-colored markers, 1 per child
• Rulers, several per table

Class Time Directions

1. To demonstrate cohesion and surface tension, look at a penny. Make a prediction. How many drops of water do you think can sit on top of the penny before the water falls off? Share your predictions with someone. Next, gently add water drops to the top of your penny and look at the shape of the water drop. Does it look rounded on top? Keep counting drops until the water falls off. Did you have more water drops than you predicted? Surface tension helps the water to form a rounded shape because the water molecules stick together—the property of cohesion we talked about. Surface tension allows some things to float on top of the water. It also allows insects to walk on the surface of water without sinking.

2. To demonstrate adhesion (water molecules sticking to different molecules), fold a paper towel into a long, narrow shape. Use a marker to make a small, dark circle 2 inches above the bottom of the paper towel. Do the same with the printer paper. Then stick the ends with the dots in the water. Observe the change over time. Did you notice the water level rise in the towel and paper? Did you notice the marker color begin to rise with it? Was there a difference in the speed of water rising in each piece of paper? Why do you think there was a difference? Adhesion is at work. Adhesion lets water get absorbed and stick to other things. That's why paper towels and cloth can absorb water. Adhesion also helps explain, in part, how water pushes against gravity and rises in plants, so plants can get the nourishment they need.

Now we've seen through many examples that water is truly a unique substance only God can create!