Many children can identify that water exists in 3 states within our natural environment. Understanding that it is the very same water that undergoes changes of state presents far more of a challenge to children in grade 2. The following experiment is simple yet effective in helping children understand changes in state and a rudimentary understanding of the water cycle.
This video shows how to make liquid carbon dioxide using a plastic pipette.
There are three main states of matter – solids, liquids, and gases. Each of these states is also known as a phase. Materials can move from one phase to another when physical forces are present. One example of those forces is temperature. The phase or state of matter can change when the temperature changes. Changes of state are energy dependent; they are the product of how particles are interacting with each other. Temperature and pressure affect the way particles interact to change a state or phase. Increase the temperature (a measure of the average speed of particles in an object) and you increase the speed or disorganization of the particles in the object and get a change of state. Increase the pressure and you increase the organization of the particles in the object of study and you get a change of state. These changes of state are a fundamental property of the material. Generally, as the temperature rises, matter moves to a more active state.
Here’s a fun activity from Carolina Biological Supply in which students can grow their own snowflakes using household materials and dry ice. Check for businesses in your area that supply dry ice. Be sure to follow the suggestions for the safe handling of dry ice.
One could say that snowflakes are simply frozen water — but if you compare a snowflake to an ice cube, you’ll notice a big difference. Why are all snowflakes six-sided? Why are none of them exactly the same? And how do we ski on them? Maruša Bradač sheds light on the secret life of snowflakes.
Lesson by Maruša Bradač, animation by bottomless well films.