Particles are always moving? How? Why? Particles behave differently in different states of matter? These invisible assumptions are difficult to explore conceptually without tools like online simulations that can guide students to make and test particle models. In this lesson, students use an online simulation to explore different states of matter. This lesson relates directly to the MS-PS1 Matter and its Interactions performance indicator that asks students to, "Develop a model that predicts and describes changes in particle motion, temperature, and state of a pure substance when thermal energy is added or removed" (MS-PS1-4).
Additionally, this as students demonstrate their understanding of the particle model, they access important cross cutting concepts and science practices related to:
1) Energy and Matter: Energy may take different forms and he transfer of energy can be tracked as energy flows through a designed or natural system (CCC).
2) System and System Models: Models can be used to represent systems and their interactions—such as inputs, processes and outputs—and energy, matter, and information flows within systems (SP2 and CCC).
3) Patterns: Macroscopic patterns related to the nature of microscopic-level structure of matter (CCC).
4) Scale, Proportion, and Quantity: Time, space, and energy phenomena can be observed at various scales using models to study systems that are too large or too small (CCC).
This lesson can be used separately, but it also works as a creative assessment strategy to conclude a unit of study about states of matter. The sequence of these related lessons occurs as is follows:
2) States of Matter Simulation Investigation (this lesson)
In order to ENGAGE students in this lesson, students use the States of Matter Simulation Investigation to complete a background information section to help them access related vocabulary. Students also make predictions, using words and pictures, about how they think particles move in different states of matter. Students answer two predictive questions that can act as hypotheses to help them frame their investigation:
1) If you start with a substance as a solid, what will happen to the molecules as you add thermal energy (heat)?
2) Will the kinetic energy of a substance be greater in a gas, liquid or solid? Why?
A quick stand up poll of student ideas can provide a neat opportunity for students to hear each others' diverse predictions. Stand up polls involve students standing up to show their ideas as a response to poll questions like these:
Who predicted gas particles will move fastest?
Who predicted gas particles will move slowest?
Who predicted liquids have the most energy?
Who predicted solids will have slow particle speed?
The EXPLORE stage of the lesson is to get students involved in the topic so that they start to build their own understanding. To help students explore, students access either the States of Matter or States of Matter Basics online simulation from the University of Colorado PhET project and work through the activities in the States of Matter Simulation Investigation.
Teacher Note: Students love simulations! Part of the draw is that simulations feel like games, which makes them highly engaging. In order to satisfy the crave to play, I've found that giving students 10 minutes of "mess around" time at the beginning of the exploration process helps more students stay on task later. Depending on your students' attention span, level of engagement and impulse control, it may be beneficial to utilize any (or all) of the of the following strategies when conducting investigations online:
1) Remind students of norms for digital citizenship (safe searching, access only the assigned site, refrain from social media).
2) Monitor progress and/or build in timed checkpoints. Students can easily "get lost" in these simulations because they seem like games.
3) Use strategic partnering. Pair students who have challenges with staying on task or comprehending difficult concepts with students who can model appropriate learning behaviors.
4) Chunk the investigation. This investigation is very long for one class period. If time and technology allow, it may be beneficial to break the investigation into two parts or specify an end point.
The EXPLAIN stage provides students with an opportunity to communicate what they have learned so far and figure out what it means. This stage of the lesson presents a great place for a quick formative assessment. To help students explain and process their learning, students participate in a strategy called, "All Play". For more on this review strategy, view this video:
For more on inclusion and expectations for participation, read this section's reflection: Expecting Everyone to Participate.
The EXTEND stage allows students to apply new knowledge to a novel situation. The novel situation in this case is to apply the particle model of matter to plasmas. The extension opportunity is on page 5 of the States of Matter Simulation Investigation. This extension asks students this question:
This simulation only simulates the particle models for solids, liquids and gasses. Use patterns and evidence from this investigation to predict how particles would behave in plasma. What is the kinetic energy of the particles? What might you expect the temperature to be relative to a liquid or gas?
Additionally, students draw a particle model of what they think the particles will behave like in a plasma. Students can then research plasmas to discover if their predictions are accurate.
For a creative option, students can create a Change of State Flipbook:
Make a “States of Matter Flip Book! Cut at least 10 small and equal squares of paper. Starting with a solid, and progressing to a gas, show what happens to the particles as energy increases. Include labels of the state of matter, a source of energy (such as a fire or hot plate) and use color to show the motion and shape of at least 10 particles in a container.
The EVALUATION stage is for both students and teachers to determine how much learning and understanding has taken place. At the conclusion of this lesson, students should have a solid foundation for using the particulate model of matter to justify different states of matter. In order to evaluate understanding, a quick quiz: Changes of State Quiz offers a glimpse into the "remember" and "understand" levels or knowledge (Bloom's Revised Taxonomy). The following resource can also be used as an evaluation or relearning tool: Changes of State Relearn and Reassessment Activity. Review of student work provides additional insight into students' abilities to explain what they have learned about states of matter:
After students show that they have a basic conceptual understanding, providing students with an opportunity to practice and prove competence in a more open-inquiry investigation is an important evaluation method. This additional evaluation gives insight into whether students can "apply" their level of understanding. There are two investigations that could provide application opportunities: State of Matter Goop Investigation or Hot and Cold Investigation.