GRADE EIGHT CURRICULUM. Unit 1: The Makeup and Interactions of Matter

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1 Chariho Regional School District - Science Curriculum September, 2016 GRADE EIGHT CURRICULUM Unit 1: The Makeup and Interactions of Matter OVERVIEW Summary The performance expectations for this unit help students formulate an answer to the question, How do atomic and molecular interactions explain the properties of matter that we see and feel? Students will build understanding of what occurs at the atomic and molecular scale. Students will understand that pure substances are made of a single type of atom or molecule and that they have characteristic chemical and physical properties. They will be able to explain at a molecular level the states of matter and changes between states, that chemical reactions involve regrouping atoms to form new substances and that atoms rearrange during chemical reactions. Students will also understand that the number of atoms involved at the start of a chemical reaction does not change after the reaction has taken place. They will apply their understanding of chemical reactions to the processes of photosynthesis and respiration. Students will account for the molecules involved in these processes to show their role in how matter and energy cycle through an ecosystem. Content to be Learned Substances are made up of different types of atoms which can combine with one another in various ways and form new substances. Atoms form molecules that range in size from two to thousands. Pure substances have characteristic physical and chemical properties that can be used to identify the substance. Substances react chemically in characteristic ways. In a chemical process, the atoms that make up the original substances are regrouped into different molecules which have different properties from those of the reactants. The total number of each type of atom is conserved, and thus the mass does not change. Within individual organisms, food goes through a series of chemical reactions in which it is broken down and rearranged to form new molecules, to support growth or to release energy. The process of photosynthesis is an important component in cycling matter and the flow of energy. Cellular respiration in plants and animals involve chemical reactions with oxygen that release stored energy. Complex molecules containing carbon react with oxygen to produce carbon dioxide and other materials. Practices Collecting and analyzing qualitative and quantitative data. 1

2 Developing, interpreting, and using models. Constructing explanations and design solutions. Obtaining, evaluating and communicating information. Crosscutting Concepts Scale, proportion and quantity. Patterns. Energy and matter. Structure and function. Essential Questions How are the characteristic properties of an element affected when the element is combined with another element? How do different chemicals interact? What factors affect these interactions? How do living things use these interactions to survive? 2

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5 Unit 2: Thermal Energy and Matter OVERVIEW Summary The performance expectations will begin to help students formulate an answer to the question, How can energy be transferred from one object or system to another? Students will understand the difference between temperature (the average kinetic energy of the particles in a substance) and thermal energy (the total amount of kinetic energy within a substance), and that adding or removing thermal energy will increase or decrease the kinetic energy of the particles within a substance and this can result in a change of state. Students will also be able to apply an understanding of design to the process of energy transfer. Students will understand that the amount of energy needed to change the temperature of a substance depends on the amount of the substance, the type of matter, and the environment. Students will understand that some chemical reactions store energy while other reactions release energy. Content to be Learned Gases and liquids are made of molecules or atoms that move about relative to each other. Liquid molecules are constantly in contact with each other, in a gas they are spaced except when they collide. In a solid they are closely spaced and may vibrate, but do not change relative location. The changes of state that occur with variations in temperature or pressure can be described and predicted using these models of matter. Heat in science refers to energy transferred between two objects or systems that are at different temperatures. The relationship between the temperature and the total energy of a system depends on the types, states, and amounts of matter present. Temperature is a measure of the average kinetic energy of particles of matter. Energy is spontaneously transferred out of hotter regions or objects into colder ones. The amount of energy transfer needed to change the temperature of a matter sample by a given amount depends on the nature of the matter, the size of the sample and the environment. When the motion energy of an object changes, there is inevitably some other change in energy at the same time. (Conservation of Energy) Some chemical reactions release energy, others store energy. The more precisely a design task s criteria and constraints can be defined, the more likely it is that the designed solution will be successful. Constraints include consideration of scientific principles and other relevant knowledge that is likely to limit possible solutions. A solution needs to be tested, and then modified on the basis of the test results in order to improve it. Although one design may not perform the best across all tests, identifying the characteristics of the design that performed the best in each test can provide useful information for the redesign process. 5

6 The process of testing the most promising solutions and modifying what is proposed on the basis of the test results leads to greater refinement and ultimately to an optimal solution. Practices Developing and Using Models. Constructing Explanations and Designing Solutions. Planning and Carrying Out Investigations. Engaging in Argument from Evidence. Crosscutting Concepts Cause and effect. Energy and matter. Scale, proportion, and quantity. Essential Questions What is the relationship between kinetic energy, thermal energy, temperature and heat? How does the thermal energy of particles in a substance compare to the state of matter of that substance? How is the kinetic energy of a system distributed through that system? What is the best design and materials to use to prevent the transfer of thermal(kinetic) energy between materials? 6

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10 Unit 3: Waves, Forces and Energy OVERVIEW Summary The first performance expectation in this unit will help students formulate an answer to the question, What are the characteristic properties of a wave and how can they be used? The PS4 Disciplinary Core Idea from the NRC Framework is broken down into Wave Properties, Electromagnetic Radiation and Information Technology and Instrumentation. Students will be able to describe and predict characteristic properties and behaviors of waves when the waves interact with matter. Students will be able to apply an understanding of waves as a means to send digital information. The second performance expectation will help students formulate an answer to the question, How can energy be transferred from one object or system to another? The PS3 Disciplinary Core Idea from NRC Framework is broken down into four sub-core ideas: Definitions of Energy, Conservation of Energy and Energy Transfer, the Relationship between Energy and Forces, and Energy in Chemical Process and Everyday Life. Students will understand that the interaction of objects can be explained and predicted using the concept of energy transfer from one object or system of objects to another, and the total change of energy in any system is always equal to the total energy transferred into or out of the system. Students will understand that objects that are moving have kinetic energy and that objects may also contain stored (potential) energy, depending on their relative position. Students will begin to develop an understanding of the relationship between force and energy. 10

11 Content to be Learned A simple wave has a repeating pattern with a specific wavelength, frequency and amplitude. A sound wave needs a medium through which it is transmitted. When light shines on an object, it is reflected, absorbed, or transmitted, depending on the object s material and the frequency (color) of the light. The path that light travels can be traced as straight lines, except at surfaces between different transparent mediums (e.g. air and water, air and glass) where the light path bends. A wave model of light is useful for explaining brightness, color and the frequency-dependent bending of light at the surface between media. However, because light can travel through space, it cannot be a matter wave, like sound or water waves. Digital signals (sent as wave pulses) are a more reliable way to encode and transmit information. Motion energy is properly called kinetic energy; it is proportional to the mass of the moving object and grows with the square of its speed. KE=1/2mv 2. A system of objects may also contain stored (potential) energy, depending on their relative positions. When two objects interact, each one exerts a force on the other that can cause energy to be transferred to or from the object, but the total energy will always remain the same (Conservation of Energy). For any pair of interacting objects, the force exerted by the first object on the second object is equal in strength to the force that the second object exerts on the first, but in opposite direction (Newton s third law). Practices Using Mathematical Computational Thinking. Developing and Using Models. Obtaining, Evaluating and Communicating Information. Analyzing and Interpreting Data. Constructing Explanations and Designing Solutions. Crosscutting Concepts Patterns. Structure and function. Scale, proportion, and quantity. Systems and system models. Essential Questions What happens to the energy of a system when objects change position or interact? How does the magnitude of a force affect the energy of an object? What factors affect the sum total of energy an object possesses? How are the components of a wave related to the energy the wave possesses? What are the effects on a wave as it passes through different materials? How are waves used in the communication industry? 11

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14 Unit 4: Our Solar System and Its Place in the Universe OVERVIEW Summary Students will focus on understanding ideas related to why some objects will keep moving, why some fall to the ground and why some materials are attracted to each other while others are not. Students answer the question, How can one describe the physical interactions between objects and within systems of objects? Emphasis is placed on balanced and unbalanced forces and the role mass plays on those forces (Newton s 1st and 2nd Laws) Students should be able to apply ideas about gravitational, electrical and magnetic forces to explain a variety of phenomena. Students also develop ideas that objects can exert forces on each other even though the objects are not in contact. Students will answer the questions, What is Earth s place in the universe? What makes up our solar system? How can the motions of the Earth explain seasons, and eclipses? Students examine the Earth s place in relation to the solar system, the Milky Way galaxy and the universe with an emphasis on scale. Students will use models using a systems approach to explain cyclical patterns of eclipses, tides and seasons. Students will understand that our solar system consists of the sun, and a collection of objects including planets, their moons, and asteroids that are held in orbit around the sun by its gravitational pull on them. The solar system was formed by a disk of gas and dust drawn together by gravitational attraction. Content to be Learned Earth and its solar system is part of the Milky Way galaxy, which is one of many galaxies in the universe. The solar system consists of the sun and a collection of objects, including planets, their moons, and asteroids that are held in orbit around the sun by its gravitational pull on them. The solar system appears to have formed from a disk of dust and gas, drawn together by gravity. Patterns of the apparent motion of the sun, the moon, and the stars in the sky can be observed, described, predicted, and explained with models. The motion of an object is determined by the sum of the forces acting on it; if the total force on the object is not zero, its motion will change. The greater the mass of the object, the greater the force 14

15 needed to achieve the same change in motion. For any given object, a larger force causes a larger change in motion. All positions of objects and the direction of forces and motions must be described in an arbitrarily chosen reference frame and an arbitrarily chosen unit of size. In order to share information with other people, these choices must also be shared. Gravitational forces are always attractive. There is a gravitational force between any two masses, but it is very small except when one or both of the objects have large mass- e.g. Earth and the sun. Practices Planning and carrying out investigations. Engaging in argument from evidence. Developing and using models. Analyzing and interpreting data. Cross Cutting Concepts Stability and change. Systems and systems models. Patterns. Scale, proportion and quality. Essential Questions How are the components of the universe arranged? What are the major events which lead to the development of the universe, solar system, and planetary system? What are characteristic components of a solar system? What are the forces that keep the components of the solar system in motion and balanced? What observations of the universe could explain that the motion of the planets and stars is not random but periodic and predictable? 15

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