Students engage with a phenomenon in which they observe what happens to a partially deflated mylar balloon when heat is added to it. It is a simple activity to get students thinking about how the change in heat energy affects molecules in matter. They will ask questions about what they observed and draw a model of what they think is happening to the molecules inside the balloon. They will return to their model in later episodes and modify it based on what they learn. In episode two the students will plan and conduct an investigation to further explore the balloon phenomenon (if you want, this experiment could also be used as the phenomenon for this standard.) This lab will help the students recognize that something happens to the volume of a gas inside an object when the temperature of the gas changes. Students will take a soda can with different temperatures of gas inside it and rapidly raise or lower the temperature of the gas to see how this affects the air inside the can. They will use their results to go back to their balloon model and make changes to it. Episode three introduces the students to the idea of phases of matter. They will identify what the main 3 phases of matter are by watching a Veritasium video. The video will help realize that there are misconceptions about the causes of phase changes. The students will then explore different phase changes. They will begin to think about what is happening to molecules to cause substances to change phase. In episode four the students will go to the States of Matter PhET Simulation.
This simulation will allow the students to explore what happens to the speed and distance between molecules as a substance changes states. The students can add or remove heat and observe what happens to the molecules.
The lab in episode five is meant to help students clearly observe that when matter changes phases, it is due to changes in thermal energy. After which, students will analyze the phenomena of what happens to water ice when it is placed in a beaker of rubbing alcohol in episode 6. They will identify what density is and learn to calculate the density of a substance by measuring the mass and volume of a substance. Students conclude their exploration in episode six by mathematically finding the density of various substances in all three phases. This activity also covers how to find the volume of a solid that is an irregular shape so that the density of these shapes can then be calculated. After finding the densities they will then create a graph showing how density changes with phase. They will use this graph to observe how water does not follow the pattern of other substances.
Storyline Narrative 8.1.5
What happens when molecules are heated or cooled?
What happens to air when it is rapidly cooled or heated?
Students observe changes to a mylar balloon with changes in heat. They will model their predictions.
Students will conduct a lab in which they try to heat and cool the air inside a can to observe the effect on the can.
They will use their results to go back to their balloon model and make changes to it.
What is a phase change?
Students watch a video clip to identify the phases of matter and phase changes and misconceptions about them. The students will then explore different phase changes and begin to think about what is happening to molecules to cause substances to change phase by drawing models of these phase changes.
How do molecules behave differently in a solid, liquid, or gas?
The students will use a PhET simulation to explore what happens to the speed and distance between molecules as a substance changes phases/states.
What are the cause and effect relationships of phase changes?
What effects does heat have on a substance?
Students will complete a lab in which they observe what happens to the temperature of water as it changes phase from solid to liquid. This lab is meant to help students clearly observe that when matter changes phases, it is due to changes in thermal energy.
How are density and states related?
Students will evaluate a new phenomena by analyzing what causes water ice to sink when it is placed in a beaker of rubbing alcohol. They will identify what density is and learn to calculate the density of a substance by measuring the mass and volume of a substance.
Is there a pattern between density and phase that is followed by all substances?
Students will practice mathematically finding the density of various substances in all three phases. They will create a graph showing how density changes with phase and look for patterns in their results. They will use this graph to observe how water does not follow the pattern other substances follow.