Disappearing Water

Students will observe the amount of water in an open container over time, and they will observe the amount of water in a closed container over time. Students will compare and contrast the sets of observations over time.This lesson is the second in a three-part series that addresses a concept that is central to the understanding of the water cycle—that water is able to take many forms but is still water. As students conduct the guided inquiry activity in this complete lesson plan, they observe changes in water as it evaporates.  There is background material for the teacher as well as a good set of questions that the teacher can use to guide student thinking.  Assessment is by means of examining student journal entries.

Standards & Objectives

Learning objectives: 

Purpose:

Students will observe the amount of water in an open container over time, and they will observe the amount of water in a closed container over time. Students will compare and contrast the sets of observations over time.

Essential and guiding questions: 

Questions:

  • What will happen to this wet sponge if I let it sit out in the air for a long time?
  • What will happen to the water?
  • Have you ever played in puddles outside on the sidewalk? Have you ever gone back the next day to play again? Were the puddles there?
  • If you get your clothes wet at the drinking fountain, what happens to those clothes over time?
  • Can you think of any other things like this that have happened around you?
  • What happened to the level of the water in the closed can?
  • What happened to the level of the water in the open can?
  • Is there a difference in what we saw happen between the two cans? What is the difference?
  • What did we do that was different with the cans?
  • What if we used jars instead of cans? Do you think our result would be different? Why or why not?
  • What happened to the sponge in the closed can?
  • What happened to the sponge in the open can?
  • Is there a difference between the sponges in the two cans? What is the difference?
  • Why do you think we used a closed can?
  • Why do you think we used an opened can?
  • What might be different about an open can than a closed can?

Lesson Variations

Blooms taxonomy level: 
Understanding
Extension suggestions: 

Extensions:

  • See the final Science NetLinks lesson in this series, entitled Water 3: Melting and Freezing.
  • Read Puddles by Jonathan London (illustrations by G. Brian Karas) and ask students the following questions:
  • Where did the puddles and baby rivers come from?
  • What will happen to the puddles over time?
  • Will it take longer for this to happen to the big puddles or the small puddles? Why do you think this?
  • What will happen to the wet grass over time?
  • What will happen to the mud?
  • You go out into grass early in the morning and your shoes get wet. Later in the afternoon you notice that your shoes do not get wet. What happened to the water/dew that was on the grass?
  • If the children in the story had left their coats out in the rainstorm, what would have happened to their coats if they were left outside over time? What if the coat was put into a plastic bag and shut? Would this still happen? Why or why not?

Helpful Hints

Materials:

  • coffee cans with lids
  • water
  • wooden stirring sticks
  • markers
  • paper for journal entries

References

Contributors: