Mr. Loar’s science students are learning about physical and chemical changes, and the winter season offers inspiration for some fun and instructive related science experiments, whether in the classroom or at home.
First students reviewed the difference between physical and chemical changes:
In a physical change, the appearance or form of a substance changes but the kind of matter in the substance does not. (Chemical bonds are not formed or broken, and no new substance is created.) For example: water frozen into ice, a wax candle melting, or popcorn when it’s popped.
In a chemical change, however, the kind of matter changes and at least one new substance with new properties is formed. When a chemical change occurs, it leaves behind clues or indicators such as a change in color, formation of a solid, or the creation of bubbles (indicating a gas.)
The color-changing milk experiment uses milk, food coloring, dish soap, and a few household items. Simply pour milk into a dish then add a cookie cutter to the dish. Next drop food coloring into the milk surrounding the cookie cutter. Finally, coat a cotton swap with dish soap then touch it to the milk—watch the reaction as the soap breaks apart the proteins and fats of the milk!
DIY slime made with school glue, baking soda, and saline solution offers another example of a chemical reaction. The school glue is runny and “liquidy” until it’s combined with the baking soda and the saline solution. Make winter-inspired slime with blue food coloring and glitter.
Build a snowman from the warmth of your home or classroom using fake snow. Then watch and hear the chemical reactions as you pour vinegar over your creation. Modify your experiment by incorporating dish soap into your snow and observe how the reaction changes.