Essential Science for Teachers: Physical Science
Extending the Particle Model of Matter Featured Classroom: Linda Block, Castro Valley, CA
Linda Block, Castro Valley, CA
“I think that the process skills of making observations, asking questions, comparing things, coming up with hypotheses, designing experiments, reasoning from data and making generalizations, all need to happen in a context where the kids have real and rich content to work with.”
School at a Glance:
Independent Elementary School
Castro Valley, CA
- Grades: K-5
- Enrollment: 495
- Students per Teacher: 23
6% African American
1% Native American
2% Pacific Islander
- Percentage of students receiving free or reduced-price lunch: 3% versus a state average of 56%
The Independent Elementary School is located in suburban Castro Valley Unified School District, about 30 miles east of San Francisco. It is an ethnically diverse school whose Academic Performance Index (API) rank has been 10 out of a possible 10 for the past three years.
Linda Block has been teaching for seventeen years, the past seven in Castro Valley and the first ten in the San Francisco Unified School District. She has taught second through eighth grades, but most of her teaching experience has been with fourth and fifth graders. For two years she left the classroom to become a teacher in residence at the Exploratorium’s Institute for Inquiry, where she worked with teachers in classrooms and provided professional development.
Linda describes her philosophy of teaching this way: “I try to teach, whether it’s writing or science or art or history, in a way that allows my students to ask their own questions, find their own answers, and come to their own understandings. So I would say I teach in a more constructivist way, if I had to apply a label to it.”
Lesson and Curriculum
Electrostatics Exhibits; The Exploratorium, “Open Pathways”
Lesson at a Glance:
Curriculum: The Exploratorium, “Open Pathways”
Topic: Electrostatics Exhibits
In this lesson, Linda Block’s fifth graders explore the electrostatic properties of materials through classroom activities and a field trip to the Exploratorium in San Francicso.
Adapted from the Exploratorium’s “Open Pathways” materials for teachers, the intent of this lesson is for the students to rub a clear plastic tube with different kinds of cloth in order to see if there are differences in the number of Styrofoam chips that can either be picked up or moved around inside of the tube. Linda identified the challenge for fifth graders in this way: “The idea that there is a charge in there or that there are electrons moving from something that seems like it’s solid, is one that doesn’t come naturally to students. So I think the more they are able to work with materials that allow them to actually feel forces, and to notice that certain things really are attracted to others, the more it helps them make the connection to what they learned in 4th grade about forces in magnets. So these are important first steps.”
Another important component of the lesson is the process skills that Linda developed while at the Institute for Inquiry at the Exploratorium. She explains, “In terms of inquiry, this would be the beginning, where they were just exploring with materials to kind of see what they do and to help them generate questions. And that was what I saw happening. There were a few little starting points or paths that some of the kids were going down, particularly around having the pieces of fabric in front of them and then wondering if they all would have the same result. I was impressed that some of them were being pretty systematic about trying them out.”
When students got to the Exploratorium, they were able to recognize, compare, and build on their experiences in the classroom. With the help of an “explainer,” they explored a variety of exhibits in which friction between different materials results in either “attractive” or “repulsive” behavior. According to Linda, “One of the things that’s nice about taking the students on a field trip is that often times something doesn’t necessarily make sense the first time you do it in a particular way. So while somebody might be puzzling over a particular question that we’ve been exploring in class, going to the museum and being able to play around with that idea at a number of different exhibits helps students learn. They might not get it the first time but hopefully, after they’ve worked with three or four or five different exhibits that all have to do with the same content area, one of them will provide an open door for someone to understand something in a new way that they didn’t understand before.”
Session 1 What Is Matter?: Properties and Classification of Matter
What is matter? This question at first seems deceptively simple — matter is all around us. Yet how do we define it? What does a block of cheese have in common with the Moon? What are the characteristics of matter that set it apart from something that is definitely not matter? Matter is one of the big ideas in science. Most areas in physical science can be discussed and explained in terms of matter or energy, and matter is a subject that naturally bridges to the other sciences (chemistry, life, earth science, etc.). In this session, we’ll build a working definition of matter, learn to distinguish between its “accidental” and “essential” properties, and explore it through classification, an activity with a rich history in science.
Session 2 The Particle Nature of Matter: Solids, Liquids, and Gases
What simple idea links together all of chemistry and physics? How can a close study of the macroscopic differences among solids, liquids, and gases support a microscopic model of tiny, discrete, and constantly moving particles? In this session, participants learn how the "particle model" can be turned into a powerful tool for generating predictions about the behavior of matter under a wide range of conditions.
Session 3 Physical Changes and Conservation of Matter
What happens when sugar is dissolved in a glass of water or when a pot of water on the stove boils away? Do things ever really "disappear?" In everyday life, observations that things "disappear" or "appear" seem to contradict one of the fundamental laws of nature: matter can be neither created nor destroyed. In this session, participants learn how the principles of the particle model are consistent with conservation of matter.
Session 4 Chemical Changes and Conservation of Matter
How can the particle model account for what happens when two clear liquids are mixed together and they produce a milky-white solid? What happens when iron rusts? Where do the elements come from? In this session, participants extend the particle model by looking inside the particles, learn about some early chemical pioneers, and in the process discover how the law of conservation of matter applies even at the scale of atoms and molecules.
Session 5 Density and Pressure
What makes a block of wood rise to the surface of a bucket of water? Why do your ears pop when you swim deep underwater? In this session, participants examine density, an essential property of matter. They also look at how particles of matter are in constant motion, which leads to a deeper understanding of fluid pressure. Lastly, the concepts of pressure and density are investigated to explain the macroscopic phenomenon of rising and sinking.
Session 6 Rising and Sinking
Why does a hot air balloon rise into the sky? Why does ice rise in water, when a lump of solid wax will sink in a jar full of molten wax? In this session, participants generalize the model that has been developed about what rises and what sinks, using the idea of balance of forces.
Session 7 Heat and Temperature
What makes the liquid in a thermometer rise or fall in response to temperature? Which contains more heat — a boiling teakettle on the stove or a swimming pool of lukewarm water? In this session, participants focus on the difference between heat and temperature, and examine how both are defined in terms of particles. The particle model is then used to explain a number of everyday phenomena, from why things expand when they are heated to the role that temperature plays in changes of state.
Sessions 8 Extending the Particle Model of Matter
In this session, participants extend their understanding of the particle model to explain additional macroscopic phenomena, including the electrical properties of matter. Participants review the progression of ideas covered in the course and anticipate future developments in the understanding of matter.