Highlighted Phenomena from Integrated Grade 7
- A bicycle tire has low air pressure in the morning, but the air pressure gets higher later in the day after being ridden on hot pavement.
- People get hot when they exercise.
- California’s two mountain ranges run parallel to its coastline.
- Over just three days in 1982, heavy rains triggered more than 18,000 landslides in the San Francisco Bay Area.
- A landslide in Northern California blocked the path of steelhead trout returning to their spawning grounds.
Introduction to Integrated Grade 7
The guiding concept in grade seven builds on students’ understanding of systems from grade six: “Natural processes and human activities cause energy to flow and matter to cycle through Earth’s systems.” Students track the cycling of matter and energy in chemical systems (IS1), food webs (IS2), the water cycle (IS2), and the rock cycle (IS3). Near the end of the year, students examine how human activities alter these systems.
What does it mean for a product to be “all natural”? To answer this question in IS1 (Organisms and Nonliving Things Are Made of Atoms), students develop detailed conceptual models of how atoms interact and change as they heat up or are involved in chemical reactions. They use this model to explain everyday phenomena, such as the air pressure in their bike tires, snow-capped mountains rising above hot valley floors, and the transformation of natural resources into synthetic materials and products.
One of the challenges of the CA NGSS is that students must use models of microscopic mechanisms to explain everyday phenomena. A vignette in IS2 (Matter Cycles and Energy Flows through Organisms and Rocks) shows teachers how to guide students through these various scales. They begin at the macroscopic level and observe changes in an ecosystem, zoom in to define the exact molecular changes of photosynthesis, then zoom back out to see how organisms use molecules of food for energy and to build their bodies. In an engineering challenge within the vignette, students design a food calorimeter that measures the amount of energy stored in food. They describe how the device works at both the classroom and molecular scale. Students apply a similar methodology to the physical and chemical changes to rocks.
When students look at a map of California’s mountains and valleys, they consider questions about the forces that shaped our state and provide some answers. Students must not only be able to explain these features in terms of plate tectonics, but their explanation should be based on a model that shows how the flow of energy drives the cycling of matter. Instructional segment 3 (Natural Processes and Human Activities Shape Earth’s Resources and Ecosystems) describes investigations students can conduct and information they can obtain to help develop such a rich model. Students finish IS3 by applying a similar methodology to explain how the cycling of matter in an ecosystem is also driven by the flow of energy.
After having developed robust models of natural systems, students are ready to apply models to predict and explain changes to those systems in IS4 (Sustaining Biodiversity and Ecosystems Services in a Changing World). Students begin by considering the phenomenon of landslides and their role in shaping the physical environment. In an engineering connection, they design a landslide early warning system that can save lives. Students then consider how a physical change like a mega-landslide event can disrupt an ecosystem. A snapshot describes a student-driven capstone project where students develop a plan to restore a habitat that has been changed by human activities.
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.