Modeling Water
A good way of helping your students understand the different properties of water is to have a set of parallel activities that introduce them to the phenomena and the model. By oscillating back and forth, and by using models to explain the various experiments with water, students come to understand the states of matter, water, its properties, and the nature of models.
Materials
Use a large number of materials so that it is not self-evident which materials to use to make a model. Some useful ones are:
- Styrofoam balls of different size, golf balls
- plasticene
- string
- sticks of various materials, popsicle sticks,
- wire of varying strength
Activity 1
Display a variety of materials in each of the three states: solid, liquid, and gas. Ask children to describe the properties of these materials. Ask children to build a model for each of these materials that behave like the substances displayed. For example, the following are possible solutions:
Activity 2
You may want to do an experiment in which students freeze water or melt ice. Have them measure the temperature during the process. Once they are done, ask students to explain the tradition using their model.
Concepts: Energy is needed (heat) to break the bonds as the solid goes to a liquid. Energy (heat) needs to be taken out of the water to turn to ice.
Activity 3
Boil water. Ask students to observe. Record the temperature of the water as you heat it (as demo or as activity). Ask students to explain their observations using the models, liquid and gas.
Concepts: Energy is needed (heat) to break the bonds as you go from liquid to gas. The reverse happens when you go from gas to liquid, energy is released in the form of heat.
Application: This is why a burn from water vapor at 100 degrees C is much worse than a burn from water at 100 degrees C.
Activities. . .