Middle school students need to understand density and also need to be able to use the formulas to calculate density, mass, and volume. Here are some activities to help build depth to your density unit.
- Start with a phenomenon. An easy one is a latex balloon filled with helium and another balloon filled with air. Most students know that helium floats, but do they know why? Even something as simple as cereal that floats in milk (Cheerios) versus cereal that sinks (granola) can spark curiosity. You can try the diet soda versus regular soda experiment also (diet soda floats).
- Let students explore. Whether you’re remote or face to face, students can pour different liquids together to see how they stack up. There isn’t a student alive who doesn’t love the density column experiment. You find 3 or 4 or 5 or 6 liquids of different densities and pour them into a graduated cylinder, one at a time, densest liquid first. If you’re smart, you’ll be sure the liquids have different colors to make the effect more dramatic. Great success with all or some of these: pancake syrup (density = 1.37 g/mL), antifreeze (1.11 g/mL), salt water (density =1.03 g/mL), canola oil (density = 0.92 g/mL) and isopropyl alcohol (density = 0.79 g/mL).
- You’re going to have to teach students how to use D=M/V to calculate density, mass and volume. When I’m teaching remotely, I don’t have a white board to write on so I use interactive notebooks. Here’s what the interactive notebook for my density unit looks like.
4. A more formal lab that you could do with students if you were face to face is to have them determine how the density of ocean water is related to salinity and temperature. This is an important component of understanding global circulation and climate change and is a great way to give students some experience with bigger pictures. Have students measure mass and volume of water as it is heated and then calculate density. Even with classroom lab materials, it is possible to see a change in density between ice water and heated water. Then have students measure mass and volume of tap water and salt water, then calculate density. It’s easy to see that saltier water is more dense.
5. Practice, practice, practice. Students need practice calculating density, mass and volume. I give my students a fast pin link to Boom cards so they can practice whenever they want. I also have used a magic pixel self checking digital worksheet – when students get the answer correct, part of the picture is revealed.
6. Challenge. My students love escape rooms and breakouts. Working hybrid or remotely has limited our ability to do this so I’m working on creating digital escape activities for them. If you haven’t tried a digital escape activity in your class yet, here is a link to a free full length escape activity about weather.
What is your favorite density classroom activity?