Chemical Changes
Physical Science
Grades 4-5 | 20 sessions
Students learn about evidence of chemical reactions and about what happens with atoms and molecules in chemical reactions. They also learn to pose questions and use text features as they read, and to write scientific procedures. They learn and use scientific vocabulary such as reactant, atom, evidence, and experiment.
Approach
Do it:
Students engage in hands-on activities such as observing a dramatic (but safe!) reaction made by combining several substances. Students also conduct their own experiments involving chemical reactions.
Talk it:
Students are provided with many opportunities for small group discussions to help them make sense of science ideas. For example, students discuss their observations, and present posters that describe their experiments to the class.
Read it:
Students read five science books, including Handbook of Chemical Investigations, a reference book that students use as they design their own experiments. Students use comprehension strategies such as making inferences, and learn how to navigate informational text.
Write it:
Students write scientific procedures, including a procedure that describes the steps of their experiment. Throughout the unit, students write to record observations and reflect on their learning.
Learning Goals
| Science | Literacy |
|---|---|
Science Knowledge
Science Inquiry
Nature and Practices of Science
|
Reading
Writing
Listening/Speaking
|
Science Content
The Chemical Changes unit teaches students about chemical reactions. Students learn about the observable evidence of chemical reactions, and about what happens with atoms and molecules during a chemical reaction.
Evidence of chemical reactions: A chemical reaction occurs when two or more substance (reactants) combine and change to form new substances (products). These new substances have different properties than the original substances. Color change, temperature change, producing gas, and giving off light can all be evidence of a chemical reaction. A chemical reaction does not necessarily happen every time two or more substances are mixed. Scientists conduct experiments to learn more about particular chemical reactions.
Atoms and molecules in chemical reactions: All matter is made of tiny particles called atoms, and a group of atoms bonded together is a molecule. There are just over 100 different kinds of atoms, and information about the kinds of atoms are found in the periodic table. In a chemical reaction, the atoms of the reactants rearrange to form the product molecules. All the atoms in the products are the same atoms that were in the reactants. This unit does not teach students to balance chemical equations, a skill students will learn in later grades.
