Water is Cool, Day Two
Lesson 2 of 17
Objective: SWBAT predict and experiment with water in a variety of ways to understand cohesion and adhesion.
Reminders and Hints
To begin day two, I go over the list of ideas, reminders, and hints that the students came up with after their first experiment. This included taking turns, being respectful, and writing lots of notes in their observations. Another big one was actively listening and not going too fast. We reviewed these and then went over the expectations again for the experiments they are conducting. I remind them again that they need to predict, write observations, and then write what actually occurred at the end.
I ask the materials specialist to get one tub for their group. Inside these tubs is all the materials they will need for todays experiments. I am going to pace the experiment by telling them which experiment we will do first and the materials needed for it. Students will then set up their work area, write a prediction, and conduct the experiment while writing observations. The final two steps will be recording on their data sheet what actually happen and cleaning up the work area for the next experiment. We will do these steps for all the experiments.
What Was My WOW
After cleaning up the work areas, and getting materials put away, we are ready to go over our learning. I begin by asking the class to share their results with each other. I ask them to tell me if the water seemed to be attracted or not attracted to the different items they used. In the paper towel experiment water seemed to go against gravity by going up, and this is do to the attraction water has. It could only get so far before gravity finally won. I then ask the class what was the most amazing thing you saw the water do. We briefly discuss their observations and have students confirm with a thumbs up if they saw this too.
Cohesion and Adhesion
I want to explain cohesion and adhesion now that they have seen them in action. I start by explaining cohesion to students that this occurs when water is attracted to itself. I ask the class if they can look back at their notes and determine which experiment might be an example of this. The dropping water on the penny and the pennies in water are the ones I am looking for. To further explain, I ask them to look at the picture they drew with the pennies in water. I ask if anyone can remember what happened as they added more pennies. Students remember the dome.
To discuss the waters surface strength I remind them of the floating paper clip experiment. During this experiment we see how the surface of the water can support things like the paper clip. I ask the class if they have ever seen bugs that look like they are walking on water. Many recall this and I explain this is how they survive on the top of water and do not sink.
Finally, I explain that adhesion occurs when water is attracted to other objects. I ask if we saw that occur in any of our experiments. Students think about the floating paper clips and one student remembers the yarn I did the day before. I confirm that this is a god example of adhesion.