Essential Science for Teachers: Physical Science
Chemical Changes and Conservation of Matter Interactive Activity: 5-Question Survey
5-Question Survey: Chemical Change
The series of questions presented in this activity will help you find out your ideas or your students’ ideas about matter. As highlighted in this video series, when we articulate our misconceptions, we are taking the first step to rectifying them.
Surveying is one of many educational strategies that teachers can use to elicit ideas. Even a brief survey, such as the one presented next, can provide a learning opportunity for students and teachers alike. Students can reveal their misconceptions for the first time as well as open their minds to accepting scientific points of view. Teachers can form a basis for making instructional decisions, whether to validate students’ correct yet unsure ideas, confront student misconceptions, reinforce ideas that are forming, or complement ideas that are accurate but only partial explanations.
Before you complete the survey, please identify who you are (pick just one):
The answer is B: evaporation. Evaporation involves only one substance, and the particles of the substance are the same whether in liquid or gas phase. All other processes result in the creation of different particles from those initially present.
The answer is C: compound is to molecule. An element is a pure substance with the fundamental particle being called an atom. Similarly, a compound is a pure substance with the fundamental particle being called a molecule. Both a mixture and a solution are not pure substances because they are made of at least two different kinds of particles.
The answer is D: the same as before. Any chemical change is still subject to the law of conservation of matter. Particles may be torn apart and rearranged, but no atoms are created or destroyed, so the mass is conserved.
The correct answer is A: a gas being produced and escaping into the air. Because this system is not “closed” (i.e., all parts are captured and measured), the escaping gas floats away into the air and is no longer registered on the scale.
The answer is C: achieved by passing an electric current through it, splitting the molecules apart. Because hydrogen and oxygen are different substances from water, this process is not a physical change. In the video for this session, we saw an electric current used to rearrange the molecules of water into new molecules of hydrogen and oxygen.
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.