Surface Tension and Capillary Action
Second grade Chemistry lesson
Liaison: Tracy Long
Date: 10/30/97
Group Members: Mike Grunwald and Tracy Long
School: Tobin School
Teacher: Ms. Chartier
Materials:
2 large transparent bowls
~20 pennies
20 droppers
20 cups
detergent soap
1 test tube
aluminum foil
wax paper
paper
Procedure:
We will introduce the discussion by talking about special properties of water that
cause it to show some interesting physical properties. We will pay special
attention to cohesion and adhesion (though we may not use these words). Then,
we will distribute a penny, a cup of water, and a dropper to each student. The
students will see how many drops of water will fit on a penny. Next, we will mix
soap into the water and ask students to repeat the experiment, noticing any
differences between the properties of water and soap water.
We will attempt to explain the idea of surface tension and to demonstrate
this concept using foil. We will also show that some objects that float when
they are flat also float when they are crumpled up (like wax paper).
We will also attempt the foil boat experiment that is described in detail at:
http://medinfo.wustl.edu/~ysp/MSN/experiments/archive/857512487.Ph.html
Further demonstrations will include showing the students the miniscus in a test tube.
Throughout the lesson, we will ask students to form predictions about the penny
experiment and about the floating experiments. We will provide them with certain
facts on which to base predictions and to make conclusions. They will learn
manners in which to distinguish water from some other liquids. The lesson will
help to explain why soap water may be "slippery" or why some insects are capable
of floating on water by spreading out.
Evaluation:
We will intr
Comments:
|
