Chemical Interactions, First Edition

Grades 6 - 8

Chemistry is an inquiry into the structure, properties, and composition of matter, as well as the energy dynamics that accompany matter transformations. Students conduct experiments to observe macroscopic matter transformations, such as phase change, dissolution, and reaction, and apply kinetic particle theory to explain those transformations at the microscopic level. In the process, students learn conventions for thinking and communicating about chemical concepts. They also observe energy transfers associated with reactions and infer energy transfers associated with phase change. A diverse mix of empirical experiences and theoretical models helps students construct a solid basic understanding of the composition of their world and the interactions that maintain and transform it.

Investigation 1: In Substances students are introduced to substances as unique forms of matter.
Investigation 2: In Elements students learn that elements are the fundamental substances from which all matter is made, and that the periodic table displays all of the known elements.
Investigation 3: In Particles students are introduced to the particle theory of matter and use it to explain how gas can be compressed.
Investigation 4: In Kinetic Energy students observe expansion and contraction of solids, liquids, and gas, and explain those observationsin terms of the kinetic energy of particles.
Investigation 5: In Energy Transfer students explain heating up and cooling down in terms of changes of kinetic energy resulting from collisions between particles.
Investigation 6: In Heat of Fusion students determine the amount of heat needed to change solid water (ice) into liquid water.
Investigation 7: In Phase Change students learn that phase of matter (solid, liquid, gas) is the consequence of how particles relate to one another, and that phase can be changed by changing the kinetic energy of particles.
Investigation 8: In Solutions students observe dissolving and explain the change in the appearance of substances in terms of disintegration at the particle level.
Investigation 9: In Reaction students observe that starting substances (reactants) change into new substances (products) during reactions, and explain the change in terms of the rearrangement of atoms.
Investigation 10: In More Reactions students observe additional reactions and learn about limiting factors in reactions.