Highlighted Phenomena from Discipline Specific Grade 8
- A satellite orbiting Earth records a stronger gravitational pull over an area after a heavy rainfall has filled underground aquifers with water than during a drought.
- As students drop heavy objects into a tank of water, the amplitude of the wave depends on the size of the object.
- A car with its radio blasting causes the windows of a neighboring car to rattle.
- A railroad tanker car spontaneously imploded shortly after it was cleaned.
- When specific household powders are mixed together, the mixture heats up.
Introduction to Discipline Specific Grade 8
The physical science course for eighth grade is organized around the crosscutting concept of energy flows, cycles, and conservation. While the goal is for students to master DCIs in physical science, many of the phenomena are drawn from Earth and life sciences so that the course truly serves as a culmination to the middle grades science experience. Each instructional segment focuses on one form of energy and is sequenced such that the most conceptually simple energy form (kinetic) comes first.
An engineering connection in two parts in which students design a car bumper serves as bookends that frame IS1 (Energy of Motion). At the beginning of the instructional segment, students explore and create a first iteration. After a series of investigations into forces and motion throughout IS1, students return to the engineering connection with new eyes. They revise their design and then explain how it works using their new understanding of energy transfer.
Students investigate the factors that affect the pull of gravity in IS2 (Gravity and Energy Related to Position) by analyzing data from hands-on measurements and computer simulations. Analyzing measurements from satellites, students find that the mass of water in an aquifer affects the pull of gravity on the satellite. With this measurement data, they can detect how much water has been pumped out from one year to the next.
Instructional segment 3 (Electric and Magnetic Interactions and Energy) is motivated by understanding how electric motors work. These motors propel modern electric cars, but students can also examine motors by disassembling old electronic appliances. Students discover that motors are filled with magnets. Students perform investigations to understand magnets and electromagnets before engaging in an engineering challenge to design and build their own electric motor and then explain the different stages of energy transfer that make it spin.
How do Wi-Fi or cell phones send our voices and data across the world? In IS4 (Waves Transmitting Energy and Information), students investigate how light interacts with various objects. They obtain information about different technologies to explain how they transmit energy and information.
In IS5 (Thermal Energy and Heat Flow) and IS6 (Chemical Energy and Reactions), students progressively refine their model of matter at the microscopic scale. A vignette in IS5 helps students develop and apply this model as they consider the case of a railroad tanker car that imploded. Students learn how to represent thermal energy as the motion of particles and relate heat flow to the movement of tiny particles. They apply this model in an engineering connection to design a vehicle radiator and communicate why their radiator is better than a competitor’s.
Up until this point, students have treated matter as entire particles. Now, they understand that these particles are actually molecules made of individual atoms. In IS6, students use a combination of hands-on investigation and model development to explain how the changing arrangement of these atoms during chemical reactions causes energy to transfer. Students apply their understanding in an engineering connection to design a hand-warming pad.
from d’Alessio, Matthew A. (2018). Executive Summary: Science Framework for California Public Schools: Kindergarten Through Grade Twelve. Sacramento: Consortium for the Implementation of the Common Core State Standards.