Remember, creeks swollen with rain water can be dangerous, so take appropriate safety precautions. Following the clean-up, build a campfire on the creek bank and prepare lunch. While resting, discuss the effects of litter and trash on waterways and the environment. For this activity, you will need a pie pan, a clear bowl filled with water, and marbles. Ask campers if they think a bowl completely full of water will hold any marbles, and if so, how many.
Directions Begin by setting the bowl in the pie pan to avoid spills.
Campers inspect the bowl to see that is full. Carefully roll one marble at a time down the side of the bowl. The water will swell up above the bowl, but will not spill over. Ask campers how a bowl full of water could hold marbles. The answer is that water has a characteristic called cohesion or we say that water has a skin.