Implementing District Standards
(2.1.1) All matter is composed of minute particles called atoms. Most of the mass of an atom is concentrated in the nucleus. In the nucleus, there are neutrons with no electrical charge and positively charged protons. Negatively charged electrons surround the nucleus and overall, the atom is electrically neutral. (2.1.2) Elements and compounds are pure substances. Elements cannot be decomposed into simpler materials by chemical reactions. Elements can react to form compounds. Elements and/or compounds may also be physically combined to form mixtures. (2.1.3) Isotopes of a given element differ in the number of neutrons in the nucleus. Their chemical properties remain essentially the same.
(2.1.4) The periodic table arranges the elements in order of atomic number (the number of protons). The elements are grouped according to similar chemical and physical properties. As a result, an element's chemical and physical properties can be predicted knowing only its position on the periodic table.
(5.1.1) Minerals are the building blocks of rocks. Common rock-forming minerals found in Delaware (calcite, quartz, mica, feldspar, and hornblende) can be identified by their chemical and physical properties.
(5.2.5) The atmosphere can be described as being in a state of dynamic equilibrium that is maintained in part by plate tectonic processes that recycle atmospheric gases trapped in the ground back into the atmosphere.
(1.1.4) Understand that: Investigating most real-world problems requires building upon previous scientific findings and cooperation among individuals with knowledge and expertise from a variety of scientific fields. The results of scientific studies are considered valid when subjected to critical review where contradictions are resolved and the explanation is confirmed.
(1.2.2) The social, economic, and political forces of a society have a significant influence on what science and technology programs are pursued, funded, and implemented.
(2.3.1) The total mass of the system remains the same regardless of how atoms and molecules in a closed system interact with one another, or how they combine or break apart.
(2.4.1) Chemical reactions result in new substances with properties that are different from those of the component parts (reactants).
(2.5.1) Materials' properties determine their use. New materials can improve the quality of life. However, their development and production often raise social, economic, and environmental issues that require analyses of the risks and benefits.
6.2.2. Plant cells convert light energy into chemical energy through the process of photosynthesis. This chemical energy may be used for energy or to form plant structures. Photosynthesis adds oxygen to the atmosphere and removes carbon dioxide.
6.2.4 Photosynthesis and cellular respiration are complementary processes resulting in the flow of energy and the cycling of matter in ecosystems.
2.4.4 Energy is transformed in chemical reactions. Energy diagrams can illustrate this transformation. Exothermic reactions release energy. Endothermic reactions absorb energy.
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