Natural processes, including freezing and thawing and the growth of roots, cause rocks to break down into smaller pieces.
The California Science Framework (page 64) distinguishes between chemical weathering and physical weathering. In both cases, the term weathering is used in its technical sense in geology meaning the breaking of rocks to smaller pieces. Rainwater and groundwater are generally somewhat acidic due … Continue reading the story "Natural processes, including freezing and thawing"
Post Archives from the ‘Earth’ Category
How to identify common rock-forming minerals (including quartz, calcite, feldspar, mica, and hornblende) and ore minerals using a table of diagnostic properties
Since rocks are made of minerals, the California Science Framework recommends teaching about minerals (Standard 4b) before rocks (Standard 4a). The order of content in the standards does not imply any sequence in teaching the standards.
When students take the statewide test covering Grades 4 and 5 science standards, the test booklet will include a reference sheet with a Mineral … Continue reading the story "How to identify common rock-forming minerals (including quartz, calcite, feldspar, mica, and hornblende) and ore minerals using a table of diagnostic properties"
Ecosystems can be characterized by their living and nonliving components
This standard introduces the concept of an ecosystem. The California Science Framework (page 61) uses the terms biotic and abiotic in referring to the living and nonliving components that distinguish ecosystems from each other.
Whenever we analyze something in our world in terms of systems, we encounter a phenomenon called “nested systems” or “systems within systems within systems.” A human being can be considered a system … Continue reading the story "Ecosystems can be characterized by their living and nonliving components"
Students know electric currents produce magnetic fields and know how to build a simple electromagnet
This standard introduces the intimate connections between electricity and magnetism. As discussed in the CONCEPT OVERVIEW, electricity and magnetism are part of the same force, the electromagnetic force. In our everyday world, we tend to experience only specific, limited manifestations of this much more general force. Electricity and magnetism are much more than metallic objects sticking to refrigerators or electric … Continue reading the story "Students know electric currents produce magnetic fields and know how to build a simple electromagnet"
Students know how to build a simple compass and use it to detect magnetic effects, including Earth’s magnetic field
Earth has a magnetic field because it has a metallic core, and because it is spinning round and round on its axis. While we normally think that Earth’s magnetic field is permanent, it has actually reversed orientation many times in our planet’s billions of years of existence. However, it is very reasonable to expect that Earth’s north magnetic pole will … Continue reading the story "Students know how to build a simple compass and use it to detect magnetic effects, including Earth’s magnetic field"
The properties of rocks and minerals reflect the processes that formed them
Waves, wind, water, and ice shape and reshape Earth's land surface.
Rocks on the Earth’s surface are continually broken down by chemical and physical processes. Rainwater is slightly acidic because it contains dissolved carbon dioxide from the air. This weak acidity can chemically cause rocks to break apart and dissolve. Physical processes such as grinding by glaciers, pounding by waves, the freezing/thawing … Continue reading the story "The properties of rocks and minerals reflect the processes that formed them"
Students know how to identify common rock-forming minerals (including quartz, calcite, feldspar, mica, and hornblende) and ore minerals using a table of diagnostic properties.
Since rocks are made of minerals, the California Science Framework recommends teaching about minerals (Standard 4b) before rocks (Standard 4a). The order of content in the standards does not imply any sequence in teaching the standards.
When students take the statewide test covering Grades 4 and 5 science standards, the test booklet will include a reference sheet with a Mineral … Continue reading the story "Students know how to identify common rock-forming minerals (including quartz, calcite, feldspar, mica, and hornblende) and ore minerals using a table of diagnostic properties."
Students know how to differentiate among igneous, sedimentary, and metamorphic rocks by referring to their properties and methods of formation (the rock cycle).
Since rocks are made of minerals, the California Science Framework recommends teaching about minerals (Standard 4b) before rocks (Standard 4a). The order of content in the standards does not imply any sequence in teaching the standards.
The terms igneous, metamorphic, and sedimentary indicate the processes that formed the particular rocks. Since any given rock can be made from a wide … Continue reading the story "Students know how to differentiate among igneous, sedimentary, and metamorphic rocks by referring to their properties and methods of formation (the rock cycle)."