1. Electricity and magnetism are related effects that have many useful applications in everyday life. As a basis for understanding this concept, students know

• how to design and build simple series and parallel circuits using components such as wires, batteries, and bulbs
  
• how to build a simple compass and use it to detect magnetic effects, including Earth's magnetic field
  
• electric currents produce magnetic fields and how to build a simple electromagnet
  
• the role of electromagnets in the construction of electric motors, electric generators, and simple devices such as doorbells and earphones
  
• electrically charged objects attract or repel each other
  
• magnets have two poles, labeled north and south, and like poles repel each other while unlike poles attract each other
  
• electrical energy can be converted to heat, light and motion.

2. All organisms need energy and matter to live and grow. As a basis for understanding this concept, students know

• plants are the primary source of matter and energy entering most food chains
  
• producers and consumers (herbivores, carnivores, omnivores and decomposers) are related in food chains and food webs, and may compete with each other for resources in an ecosystem
  
• decomposers, including many fungi, insects, and microorganisms, recycle matter from dead plants and animals.

3. Living organisms depend on one another and on their environment for survival. As a basis for understanding this concept, students know

• ecosystems can be characterized in terms of their living and nonliving components.
  
• for any particular environment, some kinds of plants and animals survive well, some survive less well, and some cannot survive at all
  
• many plants depend on animals for pollination and seed dispersal, while animals depend on plants for food and shelter
  
• most microorganisms do not cause disease and many are beneficial.

4. The properties of rocks and minerals reflect the processes that formed them. As a basis for understanding this concept, students know

• how to differentiate among igneous, sedimentary, and metamorphic rocks by their properties and methods of formation (the rock cycle)
  
• how to identify common rock-forming minerals (including quartz, calcite, feldspar, mica, and hornblende) and ore minerals using a table of diagnostic properties.

5. Waves, wind, water, and ice shape and reshape the Earth's land surface. As a basis for understanding this concept, students know

• some changes in the Earth are due to slow processes, such as erosion, and some changes are due to rapid processes, such as landslides, volcanic eruptions, and earthquakes
  
• natural processes, including freezing/thawing and growth of roots, cause rocks to break down into smaller pieces
  
• moving water erodes landforms, reshaping the land by taking it away from some places and depositing it as pebbles, sand, silt, and mud in other places (weathering, transport, and deposition).

6. Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for understanding this concept, and to address the content in the other three strands, students should develop their own questions and perform investigations. Students will

• differentiate observation from inference (interpretation), and know that scientists explanations come partly from what they observe and partly from how they interpret their observations
  
• measure and estimate weight, length, or volume of objects
  
• formulate predictions and justify predictions based on cause and effect relationships
  
• conduct multiple trials to test a prediction and draw conclusions about the relationships between results and predictions
  
• construct and interpret graphs from measurements
  
• follow a set of written instructions for a scientific investigation.