This week I taught a lesson on surface tension and cohesion of water molecules. I led the students through a guided inquiry activity which asked the question "Which liquid, when rubbed onto a penny, can reduce the cohesion of water molecules?". First I had the students perform a control test, which involved using a pipette to count how many drops of water will stay on a clean, dry penny. Then the groups of students were asked to choose a liquid (orange juice, carbonated water, or soapy water) which they thought might reduce the cohesion of the water molecules, causing less drops to stay on the penny. Students made their choices and performed an experimental test. The terms surface tension, cohesion, variable, and control test were reviewed before and after the lesson.
I found that using this inquiry lesson increased student engagement, but it also caused some argument between group members over what liquid to choose and why.
No comments:
Post a Comment