Exemplar Lesson 01: Conservation of Mass Exemplar Lesson 02: Exothermic and Endothermic Reactions Exemplar Lesson 03: Nuclear Reactions State Resources: RATIONALE: This unit bundles student expectations that relate to chemical reactions, including the conservation of mass, chemical changes, energy transfer in reactions, and types of reactions. Prior to this unit, in middle school, students studied the conservation of mass and evidence of chemical reactions. During this unit, students demonstrate that mass is conserved when substances undergo chemical change and the number and kind of atoms are the same in the reactants and products. In addition, they recognize valence electrons and that the behavior of valence electrons are responsible for chemical changes. Students also analyze specific chemical reactions to identify whether the energy changes are endothermic or exothermic. After this unit, students address the environmental impact of the end-products of chemical reactions. According to the American Association for the Advancement of Science (AAAS), in the Benchmarks for Science Literacy (Project 2061) [online version], by the end of the 12th grade, students should know that scientists can bring information, insights, and analytical skills to bear on matters of public concern. Acting in their areas of expertise, scientists can help people understand the likely causes of events and estimate their possible effects. This unit s discussion of endproducts will allow students to realize that the effects of some processes can be predicted in advance and managed if necessary. American Association for the Advancement of Science. (1993). Benchmarks on-line. Retrieved April 25, 2008, from http://www.project2061.org/publications/bsl/online/bolintro.htm. MISCONCEPTIONS/UNDERDEVELOPED CONCEPTS: MISCONCEPTIONS: Students may think that chemical change changes the atoms themselves. PERFORMANCE INDICATORS CONCEPTS KEY UNDERSTANDINGS FOR LEARNERS Select a balanced equation from a laboratory investigation. Use the balanced equation to explain and demonstrate the law of conservation of mass. Present information in a diagram, and explain, in writing, how the balanced equation represents a chemical change. Demonstrate that the number and kind of atoms are the same in the reactants and products. (I.2E; I.7C) 1C, 1E; 5G Change Matter Nature of Science Critical Thinking Matter and mass are conserved in chemical reactions. The law of conservation of mass applies only to a closed system. 2012, TESCCC 09/07/12 page 1 of 7
PERFORMANCE INDICATORS CONCEPTS KEY UNDERSTANDINGS FOR LEARNERS Analyze specific chemical reactions to identify whether the energy changes are exothermic or endothermic in nature. Choose a graphic organizer to compare and contrast exothermic and endothermic reactions. (I.2D; I.7D) 1C, 1E; 3D Illustrate the nuclear reactions fission and fusion. Describe, through labels on the illustration, how nuclear reactions are used in applications, such as medicine and energy production. (I.3D; I.7E) 1C; 5G Change Matter; Energy Nature of Science Communicating Conclusions Properties Matter; Chemical Change Matter; Energy Models Energy Nature of Science Communicating Conclusions Energy is released or absorbed in chemical reactions. The energy released in chemical reactions is often thermal (heat). Nuclear reactions affect our everyday life. KEY ACADEMIC VOCABULARY SUPPORTING CONCEPTUAL DEVELOPMENT Endothermic type of reaction that absorbs thermal energy from the environment as it proceeds Exothermic type of reaction that releases thermal energy into the environment as it proceeds Fusion the process of combining atoms, resulting in new byproducts being produced and large amounts of energy being released Fission the process of splitting an atom, resulting in new byproducts being produced and large amounts of energy being released I.2 Scientific processes. The student uses scientific methods during laboratory and field investigations. The student is expected to: I.2D Organize, analyze, evaluate, make inferences, and predict trends from data. Organize, Analyze, Evaluate, Make inferences, Predict TRENDS FROM DATA Use appropriate mathematical calculations. Possible examples may include Averaging Percent change Probabilities and ratios Rate of change Use appropriate standard international (SI) units. 2012, TESCCC 09/07/12 page 2 of 7
I.2E Communicate valid conclusions. Analyze data using different modes of expression (narrative, numerical, graphical). Accurately predict trends from data. I. Nature of Science A4 Rely on reproducible observations of empirical evidence when constructing, analyzing, and evaluating explanations of natural events and processes. Communicate VALID CONCLUSIONS I.3 Scientific processes. The student uses critical thinking and scientific problem solving to make informed decisions. The student is expected to: I.3B Communicate and apply scientific information extracted from various sources such as current events, news reports, published journal articles, and marketing materials. I.3D Evaluate the impact of research on scientific thought, society, and the environment. Communicate conclusions in oral, written, and graphic forms. Use essential vocabulary of the discipline to communicate conclusions. Use appropriate writing practices consistent with scientific writing. Use charts and graphs to represent data and conclusions. Present scientific information in appropriate formats for various audiences. Communicate, Apply SCIENTIFIC INFORMATION Review scientific information from a variety of sources. Summarize and communicate scientific information from a variety of sources. Evaluate the quality and accuracy of information from research sources. Possible examples may include Search engines, databases, and other online tools Newspapers and other periodicals Published journal articles Marketing materials Other media sources Evaluate IMPACT OF RESEARCH Read technical and scientific articles to gain understanding of the impact of research. Evaluate the impact of research on society, everyday life, and the environment. Recognize how scientific discoveries are connected to technological innovations. Understand how scientific research and technology have an impact on ethical and legal practices. Understand how commonly held ethical beliefs impact scientific research. 2012, TESCCC 09/07/12 page 3 of 7
I.7 Science concepts. The student knows that changes in matter affect everyday life. The student is expected to: I.7B Recognize that chemical changes can occur when substances react to form different substances and that these interactions are largely determined by the valence electrons. Understand how scientific discoveries have impacted/changed commonly held beliefs. Recognize CHEMICAL CHANGES CAN OCCUR The role of valence electrons Valence electrons are the ones gained, lost, or shared in a reaction. Determining the number of valence electrons in a particular atom assists in understanding how the atom will react. I.7C Demonstrate that mass is conserved when substances undergo chemical change and that the number and kind of atoms are the same in the reactants and products. I.7D Analyze energy changes that accompany chemical reactions such as those occurring in heat packs, cold packs, and glow sticks and classify them as exothermic or endothermic reactions. VII. Chemistry B1 Summarize the development of atomic theory. Understand that models of the atom are used to help us understand the properties of elements and compounds. Demonstrate THAT MASS IS CONSERVED WHEN SUBSTANCES UNDERGO CHEMICAL CHANGE AND THAT THE NUMBER AND KIND OF ATOMS ARE THE SAME IN THE REACTANTS AND PRODUCTS Rearrangement of atoms in a reaction The law of conservation of mass/matter Mass is conserved when substances undergo chemical change. Law of conservation of matter The number and kind of atoms are the same in the reactants and products. Identify the parts of a chemical equation. Reactants Yield sign Product Balance simple chemical equations Analyze, Classify ENERGY CHANGES THAT ACCOMPANY CHEMICAL REACTIONS Energy diagrams of reactions Energy changes Exothermic reactions 2012, TESCCC 09/07/12 page 4 of 7
I.7E Describe types of nuclear reactions such as fission and fusion and their roles in applications such as medicine and energy production. Heat packs Glow sticks Endothermic reactions Cold packs VII. Chemistry E1 Classify chemical reactions by type. Describe the evidence that a chemical reaction has occurred. VII. Chemistry E4 Understand energy changes in chemical reactions. VII. Chemistry H1 Understand the Law of Conservation of Energy and processes of heat transfer. VII. Chemistry H2 Understand energy changes and chemical reactions. Describe TYPES OF NUCLEAR REACTIONS AND THEIR ROLES IN APPLICATIONS SUCH AS MEDICINE AND ENERGY PRODUCTION Types of nuclear reactions Fission Fusion Applications Medicine Energy Possible examples may include Radioisotopes VII. Chemistry E4 Understand energy changes in chemical reactions. VII. Chemistry K1 Understand radioactive decay. VII. Chemistry H2 Understand energy changes and chemical reactions. SE# Scientific Process TEKS: Choose appropriate scientific processes to support your instruction. I.1 Scientific processes. The student, for at least 40% of instructional time, conducts laboratory and field investigations using safe, environmentally appropriate, and ethical practices. The student is expected to: I.1A Demonstrate safe practices during laboratory and field investigations. I.1B Demonstrate an understanding of the use and conservation of resources and the proper disposal or recycling of materials. I.2 Scientific processes. The student uses scientific methods during laboratory and field investigations. The student is expected to: 2012, TESCCC 09/07/12 page 5 of 7
SE# Scientific Process TEKS: Choose appropriate scientific processes to support your instruction. I.2A Know the definition of science and understand that it has limitations, as specified in subsection (b)(2) of this section. I.2B Plan and implement investigative procedures, including asking questions, formulating testable hypotheses, and selecting equipment and technology. I.2C Collect data and make measurements with precision. I.2D Organize, analyze, evaluate, make inferences, and predict trends from data. I.2E Communicate valid conclusions. I.3 Scientific processes. The student uses critical thinking, scientific reasoning, and problem solving to make informed decisions. The student is expected to: I.3A in all fields of science, analyze, evaluate, and critique scientific explanations by using empirical evidence, logical reasoning, and experimental and observational testing, including examining all sides of scientific evidence of those scientific explanations, so as to encourage critical thinking by the student. I.3B Communicate and apply scientific information extracted from various sources such as current events, news reports, published journal articles, and marketing materials. I.3C Draw inferences based on data related to promotional materials for products and services. I.3D Evaluate the impact of research on scientific thought, society, and the environment. I.3E Describe connections between physics and chemistry and future careers. I.3F Research and describe the history of physics and chemistry and contributions of scientists. The English Language Proficiency Standards (ELPS), as required by 19 Texas Administrative Code, Chapter 74, Subchapter A, 74.4, outline English language proficiency level descriptors and student expectations for English language learners (ELLs). School districts are required to implement ELPS as an integral part of each subject in the required curriculum. School districts shall provide instruction in the knowledge and skills of the foundation and enrichment curriculum in a manner that is linguistically accommodated commensurate with the student s levels of English language proficiency to ensure that the student learns the knowledge and skills in the required curriculum. School districts shall provide content-based instruction including the cross-curricular second language acquisition essential knowledge and skills in subsection (c) of the ELPS in a manner that is linguistically accommodated to help the student acquire English language proficiency. http://ritter.tea.state.tx.us/rules/tac/chapter074/ch074a.html#74.4 ELPS# C(1) 1C 1E C(3) Subsection C: Cross-curricular second language acquisition essential knowledge and skills. Cross-curricular second language acquisition/learning strategies. The ELL uses language learning strategies to develop an awareness of his or her own learning processes in all content areas. In order for the ELL to meet grade-level learning expectations across the foundation and enrichment curriculum, all instruction delivered in English must be linguistically accommodated (communicated, sequenced, and scaffolded) commensurate with the student's level of English language proficiency. The student is expected to: Use strategic learning techniques such as concept mapping, drawing, memorizing, comparing, contrasting, and reviewing to acquire basic and grade-level vocabulary. Internalize new basic and academic language by using and reusing it in meaningful ways in speaking and writing activities that build concept and language attainment. Cross-curricular second language acquisition/speaking. The ELL speaks in a variety of modes for a variety of purposes with an awareness of different language registers (formal/informal) using vocabulary with increasing fluency and accuracy in language arts and all content areas. ELLs may be at the beginning, intermediate, advanced, or advanced high stage of English language acquisition in speaking. In order for the ELL to meet grade-level learning expectations across the foundation and enrichment curriculum, all instruction delivered in English must be linguistically accommodated (communicated, sequenced, and scaffolded) commensurate with the student's level of English language proficiency. The student is expected to: 2012, TESCCC 09/07/12 page 6 of 7
3D C(5) 5G Speak using grade-level content area vocabulary in context to internalize new English words and build academic language proficiency. Cross-curricular second language acquisition/writing. The ELL writes in a variety of forms with increasing accuracy to effectively address a specific purpose and audience in all content areas. ELLs may be at the beginning, intermediate, advanced, or advanced high stage of English language acquisition in writing. In order for the ELL to meet grade-level learning expectations across foundation and enrichment curriculum, all instruction delivered in English must be linguistically accommodated (communicated, sequenced, and scaffolded) commensurate with the student's level of English language proficiency. For Kindergarten and Grade 1, certain of these student expectations do not apply until the student has reached the stage of generating original written text using a standard writing system. The student is expected to: Narrate, describe, and explain with increasing specificity and detail to fulfill content area writing needs as more English is acquired. 2012, TESCCC 09/07/12 page 7 of 7