Conservation of Matter: A Modeling Approach • As you arrive, take the first handout. • Please work on the Challenge Question.
Conservation of Matter:A Modeling ApproachCalifornia Science Education Conference 2013 Rich Hedman--Sacramento AREA Science project (CSUS) Lysa Munson--Al Arqam Middle school, sacramento Kaye Schwartz--jamesrutter middle school, sacramento
Context • The lessons you are going to experience were designed by three teachers and a facilitator engaged in the process of lesson study. • The lessons were designed for middle school students, but are applicable to students at any grade level. • All the handouts and instructions (including this PowerPoint) will be available for download from our website, so please write on the handouts we provide you. • Funding for our work was provided through a California Mathematics and Science Partnership (CaMSP) grant called Excellence in Science Education Plus (eSCI+). • The grant provides for collaboration between the Elk Grove Unified School District, Sacramento State, UC Davis, and the Sacramento Area Science Project.
Experiment #1 • Turn to the Experiment #1. • You will be given some materials. • Follow the instructions. • Record your results. • You have 8 minutes.
Let’s review the particle model of matter… The particle model of matter was developed with our students earlier in the school year.
The Particle Modelof Matter • Everything in the world is made of extremely small particles. • These particles are arranged and spaced in certain ways. • The particles in a substance can have empty space between them. • In a gas, there is a lot of empty space between the particles. • In a solid, the particles are close together and locked in place. • In a liquid, the particles are as close together as in a solid, except they can change position and move around each other. • These particles move. • All particles show some amount of motion. • Temperature is an indicator of the amount of motion.
Models in Science • Models are sets of ideas about how some feature of the natural world works. • These sets of ideas (i.e. models) can be used to explain, predict, and make sense of phenomena.
These are NOT the kinds of models we are talking about: These are physical replicasor representations that may be useful in communicating about and reasoning with underlying models.
For More on Modeling: • Join me tomorrow (Saturday) in this room from 9:30-10:30am: • Understanding Modeling, the NGSS Practices, and Day & Night
Apply Model to Construct Explanation of Your Experiment #1 Results • Apply the particle model to construct an explanation as to why the mass stayed the same before and after mixing. • On poster paper. • You must include a drawing and a written response. • Post on wall when complete. • You have 8 minutes.
Apply Model to Construct Explanation of Your Experiment #1 Results • What patterns can we see when we look across all the posters?
Experiment #2 • Turn to the Experiment #2. • You will be given some materials. • Follow the instructions. • Record your results. • You have < 5 minutes.
Discuss Experiment #2 Results • What are your results? • Why? What could have caused your results?
Experiment #3 • Obtain Experiment #3 handout. • You will be given some materials. • Follow the instructions. • Record your results. • You have < 5 minutes.
Apply Model to Construct Explanation of Your Experiment #3 Results • Apply the particle model to construct an explanation as to why the mass stayed the same before and after mixing. • On poster paper. • You must include a drawing and a written response. • Post on wall when complete. • You have 8 minutes.
Experiment #3 = Chemical Reaction • Experiment #3 was a chemical reaction. What is the evidence?
Generalizing from Specific Cases • We can use the results of all three experiments, and our posters explaining what happened at the particle level, to create a general statement about matter. • We had students work together in small groups to write a final concluding statement regarding what these experiments tell us about matter in general.
General Statement About Matter • When substances are mixed (even if there is a chemical reaction), the total mass is the same before and after the mixing. • This is because particles of matter are not created or destroyed when substances are mixed, even if there is a chemical reaction. • The number of particles of each element are the same before and after the mixing, so the total mass of everything stays the same. • This is a big idea of science: CONSERVATION OF MASS!
Which standard is this? current California standards and ngss
8th Grade CA Science Content Std. 5b. • 5. Chemical reactions are processes in which atoms are rearranged into different combinations of molecules. As a basis for understanding this concept: • b. Students know the idea of atoms explains the conservation of matter: In chemical reactions the number of atoms stays the same no matter how they are arranged, so their total mass stays the same.
NGSS Middle School Physical SciencesMS-PS1-5 Performance Expectation • Students who demonstrate understanding can: • Develop and use a model to describe how the total number of atoms does not change in a chemical reaction and thus mass is conserved.
Discuss Our Original Experiment #3? • Only if we have enough time left: • Do the demonstration. • Ask participants to explain the results. • Discuss.
Questions? • All files can be downloaded from: • http://saspcsus.pbworks.com • Rich Hedman: email@example.com • Lysa Munson: firstname.lastname@example.org • Kaye Schwartz: email@example.com Conservation of Matter:A Modeling Approach CA Science Education Conference 2013