8 th Grade Science Scope and Sequence 1 st Quarter 2016 2017 Biodiversity Definition Importance: maintaining relationships (food web, symbiotic) Human Impacts Classification Levels of Classification Dichotomous Keys Branching Diagrams (Cladograms) Adaptations of Populations Structural Behavioral Physiological Benefits of certain traits over others depending on the environment This is the main topic of the unit that manifests itself in all subcategories. It is important to introduce first so that it can be embedded into all proceeding topics. Biodiversity refers to the variety of life forms that exist within a given ecosystem, biome, or an entire planet. Higher levels of biodiversity are typically associated with healthy environments. Levels of classification identify the amount of biodiversity and health of the environment. A classification system is useful when it contributes to a deeper understanding of how different organisms are related. Dichotomous keys assist in using characteristics to identify unknowns and compare traits. Branching Diagrams show how closely related organisms are to one another. When the environment changes, some plants and animals are able to survive and reproduce while others die or move to new locations. It is important to identify the different types of adaptations that organisms are capable of forming in order to understand the entire survival process of said organism. 3rd Grade: Thriving, threatened, endangered, and extinct organisms 6th Grade: Food webs and ecosystems 5th Grade: Investigate physical characteristics associated with different groups of animals. 7th Grade: Use of dichotomous keys to identify rocks 4th Grade: Describe how environmental changes caused the extinction of various plant and animal species. 6th Grade: Ecosystems and food webs Variations in Populations Mechanisms of Natural Selection Populations predictions Fossils Evidence of things that once existed Found in sedimentary rock Relative dating (Law of Superposition) After identifying different adaptations, it is important for students to understand why some adaptations are more advantageous than others. These advantageous adaptations will be the ones that allow animals to survive long enough to breed, passing on said trait. Using knowledge of adaptations, population predictions can be made based on new stimuli to an environment, such as a new predator or natural disaster. Fossil records are evidence of the progression of adaptations over time. Sedimentary rock is best for preserving fossils because of the small sediments filling shape best that form in layers, pressurizing over time. Because of the layers of sedimentary rock, relative aging can be established based on location in rock layer with deeper layers containing older fossils (Law of Superposition). 6th Grade: Ecosystems and food webs 2nd Grade: Draw conclusions from fossils about organisms that lived in the past. 5th Grade: Analyze fossils to demonstrate the connection between organisms and environments that existed in the past and those that currently exist. 7th Grade: Sedimentary Rock structure and formation
8 th Grade Science Scope and Sequence 2 nd Quarter 2016 2017 Properties of Matter It is important to understand that properties are observed 1st Grade: Properties of solids and liquids Physical: differently: Density Solubility Physical properties can be observed using the five senses 5th Grade: Observe and measure the simple chemical properties of common substances Malleability/Ductility Shape/ Color/Hardness Chemical properties can only be observed through a chemical change taking place. 4th Grade: Collect data to illustrate that the Conductivity Changes to physical properties result in a physical change. States of Matter Changes to chemical properties result in a chemical change. Chemical: physical properties of matter can be described with tools that measure weight, mass, length, and volume. Flammability Reactivity States of Matter Solid, Liquid, Gas, Plasma Changes of State Endothermic vs Exothermic Speed and Arrangement of Particles Atomic Theory & Structure Theory development Subatomic particles Protons Neutrons Electrons In order to clarify this property of matter, the students must understand that arrangement of particles will determine which state of matter an object will fall into at any point in time. Properties of each state vary slightly: Solids, having definite shape and definite volume, are the most tightly compacted all atoms are always touching. Liquids, having a definite volume but no definite shape, are loosely compacted which makes them able to slide past each other and flow Gases, having no definite shape or volume, are spread out to fill up any space and able to move the fastest. As particles spread out due to gaining heat (exothermic) and increased speed, the states will change from solid to liquid to gas. As particles condense due to releasing heat (endothermic) and decreased speed, the states will change from gas to liquid to solid. After discussing how states and properties are affected by atoms, the students need to understand the structure of one atom and how we gained knowledge of said structure. Understanding of protons, neutrons, and electrons are necessary in order to move on to understanding trends of the periodic table. 3rd Grade: Design a simple experiment to determine how the physical properties of matter can change over time and under different conditions. 4th Grade: Physical changes in matter 5th Grade: Investigate factors that affect the rate at which various material freeze, melt, or evaporate. 8th Grade: Properties of matter Periodic Table Arrangement of Elements Periods Groups (families) Elements are arranged horizontally in periods based on Atomic Number, or the number of protons in an atom of an element. 8th Grade: Properties of matter, Atomic structure and theory
Valence Electrons Other trends Weight Reactivity Type of atom Chemical Bonding The electrons role in bonding Charge (formation of ions) Ionic Bonds Covalent Bonds Metallic Bonds Elements and Compounds Difference in chemical symbols Difference in definition Mixtures and Atmosphere Heterogeneous v Homogenous Mixtures Composition of Atmosphere Vertical family groups share similarities in physical and chemical properties, including the number of valence electrons (# electrons in the outer orbital.) Because as the Atomic Number increases across periods, the Atomic Mass (protons + neutrons) also increases, causing the heavier elements to be toward the bottom.. Valence electrons will affect reactivity because an element is only stable with a full outer orbital. Aside from the Noble Gases, who have no reactivity due to having a full outer orbital, the trend of reactivity increases from the middle toward the ends of the periodic table. Alkali Metals and Halogens are the most reactive because they only need one valence electron to be gained or given away. The periodic table can also be classified by the type of atom: metal, nonmetal, and metalloid. Each of these types share different properties, which is evident in their location on the periodic table. Based on knowledge of valence electrons and types of atoms, students will be able to predict which family groups will bond together when compounds form. Based on their knowledge of types of atoms, students will be able to classify the type of bond being used: Ionic Metal + Nonmetal; electrons are given away/taken in Covalent Nonmetal + Nonmetal: Electrons are shared Metallic Metal + Metal; electrons move freely between elements Because they use chemical bonding, elements and compounds are both considered pure substances. An element is only one type of atom; it only has one capital letter in its symbol. A compound is two or more elements chemically bonded; it will have more than one capital letter in its symbol. The chemical properties of a compound will have different properties than the elements that make it up because it is a new substance. Mixtures are two or more substances physically combined and separated. Because they are only physically combined, all parts that make up a compound keep their own properties. Homogeneous mixtures look the same throughout. Any sample of this mixture will represent the entirety of the mixture. Heterogeneous mixtures look different throughout. A portion taken is not representative of the whole. Air and Earth s atmosphere is a mixture of gases. 8th Grade: Atomic structure and theory, Periodic table 8th Grade: Properties of matter, Atomic structure and theory, Periodic table 8th Grade: Properties of matter
8 th Grade Science Scope and Sequence 3 rd Quarter 2016 2017 Physical and Chemical Changes Property change Formation of a new substance Chemical Reactions Products and Reactants Signs of a Chemical Reaction Law of Conservation of Mass Acids and Bases ph Scale Properties Formation of Ions in water Gravitational Attraction Effect of Mass and Distance Using knowledge of properties and physical versus chemical combinations, students will be able to classify changes into physical and chemical changes. Physical changes have a change to the observable properties, but no change in overall identity. Chemical changes always produce a new substance with new properties. Chemical reactions are a type of chemical change, creating new substances. When writing the chemical equation for this change, the substances combining are called reactants while the substances being created are called products. Because it is difficult to know whether a chemical is new/different, recognizing signs of chemical changes is important: gas formation, energy creation, precipitate, and permanent color change. This change in properties is proof that a new substance was made. Because the atoms are rearranging in chemical reactions, no atom is ever created or destroyed. This means that the mass of the reactants must equal the mass of the products. Acids and bases are types of compounds that have similar chemical reactions with water. Acids release a positive Hydrogen ion in water, creating the ion Hydronium, whereas bases release a negative Hydroxide ion. Because they have a similar reaction with water, acids and bases share other chemical properties. Acids and bases are measured on the ph scale which measures the percent of hydrogen in the substance. Gravity is a force affected by mass and distance. As the mass of an object increases, the gravity of the object increases. As the distance between objects increases, the gravity of the object decreases. 3rd Grade: Determine how the physical properties of matter can change over time and under different conditions. 4th Grade: Explore different types of physical changes in matter. 5th Grade: Investigate factors that affect the rate at which various materials freeze, melt, or evaporate. Observe and measure the simple chemical properties of common substances 8th Grade: Periodic Table, Atoms and atomic theory, Chemical changes 8th Grade: Properties of matter, Chemical reactions 2nd Grade: Realize that things fall toward the ground unless something holds them up. 5th Grade: Recognize that the Earth attracts objects without directly touching them. Investigate how the shape of an object influences the way that it falls toward the Earth.
Gravity Motion of objects in the solar system Because gravity is affected by mass and distance, objects in our solar system are drawn toward objects of greater mass that are close to them. All orbiting is a result of gravity. 2nd Grade: Realize that things fall toward the ground unless something holds them up. 5th Grade: Recognize that the Earth attracts objects without directly touching them. Investigate how the shape of an object influences the way that it falls towards the Earth. Provide examples of how forces can act at a distance.
8 th Grade Science Scope and Sequence Guide 4 th Quarter 2016 2017 Electricity Both electricity and magnetism are caused by a flow of electrons. Movement of electrons Electricity can flow through a connected conductive material as long as the circuit is closed and attached to an energy source. Electricity can be made without an energy source by moving a magnet through a wire coil. 4th Grade: Observe that electrically charged object exert a pull on their materials. Explain how electricity in a simple circuit requires a complete loop through which current can pass. 6th Grade: Describe how simple circuit are associated with the transfer of electrical energy. Explain how simple electrical circuits can be used to determine which materials conduct electricity Electromagnetism Movement of electrons Parts of the electromagnet Strengthening an electromagnet Magnetic Fields Movement of electrons Direction and shape of the magnetic field Earth vs magnet Magnet vs electromagnet Electromagnetism combines the movement of electrons to create a more powerful magnetic field and electricity source. An electromagnet has 3 parts: an energy source, a wire coil, and a ferromagnetic center. To strengthen an electromagnet, increase any of the three parts. Electromagnets are advantageous because they can be turned off by breaking the current. Magnetic fields are affected by the movement of electrons; magnetic fields always emerge from the North Magnetic Pole and flow toward the South Magnetic Pole. Magnetic fields are symmetrical and circular; the curve of the magnetic field line indicates the weaker area in the field. The straighter the line, the stronger the field. Earth s magnetic field is similar to a bar magnet s magnetic field, although caused by different things. Magnetism in an electromagnet is only created because of the electricity running through the wire coil around the ferromagnetic center. As long as the current flows, the ferromagnetic center is a temporary magnet. 4th Grade: Observe that electrically charged objects exert a pull on their materials. Explain how electricity in a simple circuit requires a complete loop through which current can pass. 6th Grade: Describe how simple circuit are associated with the transfer of electrical energy. Explain how simple electrical circuits can be used to determine which materials conduct electricity 2nd Grade: Experiment with magnets to determine that object can move without being touched. 3rd Grade: Explore how magnets attract object made of certain metals. 4th Grade: Explore the interaction between magnets.