8th Grade
Science
Introduction
(1) Grade 8 science is interdisciplinary in nature; however, much of the content focus is on earth and space science. National standards in science are organized as multi-grade blocks such as Grades 5-8 rather than individual grade levels. In order to follow the grade level format used in Texas, the various national standards are found among Grades 6, 7, and 8. Recurring themes are pervasive in sciences, mathematics, and technology. These ideas transcend disciplinary boundaries and include change and constancy, patterns, cycles, systems, models, and scale.
The strands for Grade 8 include the following.
(A) Scientific investigation and reasoning.
(i) To develop a rich knowledge of science and the natural world, students must become familiar with different modes of scientific inquiry, rules of evidence, ways of formulating questions, ways of proposing explanations, and the diverse ways scientists study the natural world and propose explanations based on evidence derived from their work.
(ii) Scientific investigations are conducted for different reasons. All investigations require a research question, careful observations, data gathering, and analysis of the data to identify the patterns that will explain the findings. Descriptive investigations are used to explore new phenomena such as conducting surveys of organisms or measuring the abiotic components in a given habitat. Descriptive statistics include frequency, range, mean, median, and mode. A hypothesis is not required in a descriptive investigation. On the other hand, when conditions can be controlled in order to focus on a single variable, experimental research design is used to determine causation. Students should experience both types of investigations and understand that different scientific research questions require different research designs.
(iii) Scientific investigations are used to learn about the natural world. Students should understand that certain types of questions can be answered by investigations, and the methods, models, and conclusions built from these investigations change as new observations are made. Models of objects and events are tools for understanding the natural world and can show how systems work. Models have limitations and based on new discoveries are constantly being modified to more closely reflect the natural world.
(B) Matter and energy. Students recognize that matter is composed of atoms. Students examine information on the Periodic Table to recognize that elements are grouped into families. In addition, students understand the basic concept of conservation of mass. Lab activities will allow students to demonstrate evidence of chemical reactions. They will use chemical formulas to identify substances.
(C) Force, motion, and energy. Students experiment with the relationship between forces and motion through the study of Newton's three laws. Students learn how these forces relate to geologic processes and astronomical phenomena. In addition, students recognize that these laws are evident in everyday objects and activities. Mathematics is used to calculate speed using distance and time measurements.
(D) Earth and space. Students identify the role of natural events in altering Earth systems. Cycles within Sun, Earth, and Moon systems are studied as students learn about seasons, tides, and lunar phases. Students learn that stars and galaxies are part of the universe. In addition, students use data to research scientific theories of the origin of the universe. Students will illustrate how Earth features change over time by plate tectonics. They will interpret land and erosional features on topographic maps and satellite views. Students learn how interactions in solar, weather, and ocean systems create changes in weather patterns and climate.
(E) Organisms and environments. In studies of living systems, students explore the interdependence between these systems. Students describe how biotic and abiotic factors affect the number of organisms and populations present in an ecosystem. In addition, students explore how organisms and their populations respond to short- and long-term environmental changes, including those caused by human activities.
(2) Science, as defined by the National Academy of Sciences, is the "use of evidence to construct testable explanations and predictions of natural phenomena, as well as the knowledge generated through this process." This vast body of changing and increasing knowledge is described by physical, mathematical, and conceptual models. Students should know that some questions are outside the realm of science because they deal with phenomena that are not scientifically testable.
(3) Scientific hypotheses are tentative and testable statements that must be capable of being supported or not supported by observational evidence. Hypotheses of durable explanatory power that have been tested over a wide variety of conditions become theories. Scientific theories are based on natural and physical phenomena and are capable of being tested by multiple independent researchers. Students should know that scientific theories, unlike hypotheses, are well established and highly reliable, but they may still be subject to change as new information and technologies are developed. Students should be able to distinguish between scientific decision-making methods and ethical/social decisions that involve the application of scientific information.
Unit 00: Introduction: Processes for Scientific Investigations
(1 class for the entire unit)
Students demonstrate safe practices as described in the Texas Education Agency-approved safety standards. Please refer to the TEKS Resource System Resource “Science Notebooking: A Reflective Tool for Assessing Student Understanding” (Secondary) for more information. Consider having students use scientific practices to engage in a short descriptive investigation regarding safety to begin working and thinking like a scientist and to give a purpose to begin using the science notebook.
The introduction unit is an opportunity to introduce the course through the lens of the Overarching Understandings (big ideas). Throughout the school year, students need to continually look at instances of natural phenomena through the big ideas of systems, classifications, properties, patterns, models, constancy, and change. These terms are included in Key Content Vocabulary and students should be questioned throughout each unit for instances of these big ideas. Additionally, students need to be continually aware of the processes involved in their “doing” of science.
The scientific processes are very similar throughout every science course, beginning in Kindergarten. Students may need some direct instruction on the purpose and properties of scientific processes; however, it is intended for students to develop a deep understanding of the scientific processes by using them in the context of the content of this course, throughout every unit of this course. There are no Performance Assessments or assessment items associated with the introduction.
TEKS in this unit: 8.1A, 8.1B, 8.2A, 8.2B, 8.2C, 8.2D, 8.2E, 8.3A, 8.3B, 8.3C, 8.3D, 8.4A, 8.4B
Unit 01: Investigating Atoms and the Periodic Table
(24 classes for the entire unit)
Students describe the structure of an atom including mass / size comparisons, electrical charges, and locations of subatomic particles. Additionally, students determine the electrical charge of a nucleus, based on the presence and number of positively charged protons. Students use scientific practices and a variety of tools to investigate and interpret the relationship between the information on the Periodic Table and the atomic structure of atoms / elements for the purpose of drawing, constructing, and decoding models. They calculate the number of neutrons in the nucleus by subtracting the atomic number from the mass number on the Periodic Table and identify elements based on the number of protons in an atom. Furthermore, students examine patterns in physical and chemical properties to understand the organization and placement of elements into periods and groups / families on the Periodic Table. They analyze and interpret information on the Periodic Table to ascertain why elements are arranged into groups / families. Additionally, students identify that valence electrons determine an element’s chemical properties including reactivity, and students relate an element’s structure to its placement on the Periodic Table. Students view the Periodic Table as a model and learn how the arrangement of the Periodic Table allows for the prediction of undiscovered elements and their properties. Additionally, students communicate and discuss their observations and record and organize data in their notebooks. Students continue to demonstrate safe practices as outlined in the Texas Education Agency-approved safety standards and consider environmentally appropriate and ethical practices with resources during investigations. Finally, students identify the advantages and limitations of atomic models and relate the research and development of atomic models and the Periodic Table to their impact on scientific thought and society.
TEKS in this unit: 8.1A, 8.2A, 8.2C, 8.2E, 8.3A, 8.3B, 8.3C, 8.3D, 8.4A, 8.5A, 8.5B, 8.5C
Unit 02: Investigating Chemical Formulas and Reactions
(10 classes for the entire unit)
Students learn how formulas are used to reveal the composition of substances and indicate the number of atoms of each element in a substance. They analyze chemical formulas to determine the numbers of atoms of each element present in a compound. Students use scientific practices and a variety of tools to investigate how evidence of chemical reactions indicate that new substances with different properties are formed and the relationship between chemical reactions and the law of conservation of mass. Students construct models of chemical formulas and chemical reactions and identify the advantages and limitations of models. Additionally, students communicate and discuss their observations and record and organize data in their notebooks. Students continue to demonstrate safe practices as outlined in the Texas Education Agency-approved safety standards, and consider environmentally appropriate and ethical practices with resources during investigations.
Note:
There are three perspectives that can be used to demonstrate an understanding of chemical reactions and their relationship with the law of conservation of mass, the macro level, the micro level, and scientific conventions.
Macro level investigations of chemical reactions and the conservation of mass will be the most familiar with students since they are directly related to the experiences students can have in the classroom. Students can determine the total mass in grams of the reactants, observe evidence of chemical reactions, and determine the mass in grams of the products. Students can verify that the total mass of reactants and products are equal in reactions occurring in a closed system to demonstrate the law of conservation of mass. Students can account for lost or gained mass in reactions occurring in an open system. For example, if a gas is produced and released into the atmosphere, a student can mass the remaining solid or liquid product and determine the mass of the released gas.
An understanding of the micro level perspective of chemical reactions and the conservation of mass comes from conceptual instruction of the phenomena. Students use models of chemicals and demonstrate changing bonds between atoms. Students can be expected to understand that the numbers of atoms in a chemical reaction will not change and only the arrangement of the atoms and bonds change in the chemical reaction to adhere to the law of conservation of mass.
An understanding of the scientific conventions used to illustrate chemical reactions and the law of conservation of mass is only partially expected in the streamlined TEKS. Students are no longer expected to recognize balanced chemical equations. However, an understanding of chemical formulas as a convention for representing chemicals can still be expected. Students can still be expected to recognize that a chemical equation is a representation of a chemical reaction and can be used to assess student’s conceptual micro level understanding or macro level calculations to demonstrate conservation of mass. For example, a student could be shown a balanced chemical equation with the mass of each reactant indicated and the mass of one product indicated. The student could be expected to find the unknown mass of a second product to demonstrate the relationship between chemical reactions and the law of conservation of mass (e.g., Grade 8 Science STAAR Spring 2016 item # 30).
TEKS in this unit: 8.1A, 8.1B, 8.2A, 8.2B, 8.2C, 8.2D, 8.2E, 8.3A, 8.3B, 8.3C, 8.4A, 8.4B, 8.5D, 8.5E
Unit 03: Investigating Force and Motion
(25 classes for the entire unit)
Students use scientific practices and a variety of tools to investigate, demonstrate (using models), and calculate how unbalanced forces change the speed or direction of an object's motion. Students calculate how a change in force affects the motion of an object. They also calculate the total net force acting upon an object by adding forces acting in the same direction or subtracting forces acting in opposite directions. Students also differentiate between speed, velocity, and acceleration. Furthermore, they are introduced to the relationship between force, mass, and acceleration (F=ma). Students manipulate the formula F=ma to understand how a change in force affects the acceleration (change in motion or direction) of an object. Students investigate and describe applications of Newton’s law of inertia, law of force and acceleration, and law of action-reaction. Students discuss their observations and record and organize data in their notebooks. Additionally, they analyze data to formulate reasonable explanations, communicate valid conclusions supported by the data, and predict trends. Students continue to demonstrate safe practices as outlined in the Texas Education Agency-approved safety standards and consider environmentally appropriate and ethical practices with resources during investigations.
Note: Students will be allowed the use of calculators on the Grade 8 Science STAAR Assessment.
TEKS in this unit: 8.1A, 8.2A, 8.2B, 8.2C, 8.2D, 8.2E, 8.3A, 8.3D, 8.4A, 8.4B, 8.6A, 8.6B, 8.6C
Unit 04: Investigating Global Weather Patterns
(10 classes for the entire unit)
Students use scientific practices and a variety of tools to investigate and explore how the Sun provides the energy that drives convection within the atmosphere and oceans, producing winds. In addition, they identify how global patterns of atmospheric movement influence local weather using weather maps that show pressure and frontal systems. Students identify the role of oceans in the formation of weather systems. Additionally, students communicate and discuss their observations and record and organize data in their notebooks. Furthermore, students analyze and interpret information to construct reasonable explanations based on evidence from their investigations and communicate valid conclusions (supported by collected data). Students continue to demonstrate safe practices as outlined in Texas Education Agency-approved safety standards and consider environmentally appropriate and ethical practices with resources during investigations.
TEKS in this unit: 8.1A, 8.2A, 8.2C, 8.2E, 8.3A, 8.3B, 8.3C, 8.3D, 8.4A, 8.4B, 8.10A, 8.10B, 8.10C
Unit 05: Investigating Forces that Change the Earth
(15 classes for the entire unit)
Students use scientific practices and a variety of tools to investigate and describe the historical development of evidence that supports plate tectonic theory, including contributing scientists. They demonstrate how plate tectonics relate to crustal feature formation and investigate and describe how Newton’s laws apply to Earth’s tectonic activities. In this unit, students' prior knowledge of convection can now be applied to tectonic plate movement. In addition, they interpret topographic maps and satellite views to identify land and erosional features and predict how these features may be reshaped by weathering. Additionally, students communicate and discuss their observations and record and organize data in their notebooks. Furthermore, students analyze and interpret information to construct reasonable explanations based on evidence from their investigations and communicate valid conclusions (supported by collected data). Students continue to demonstrate safe practices as outlined in Texas Education Agency-approved safety standards and consider environmentally appropriate and ethical practices with resources during investigations.
TEKS in this unit: 8.1A, 8.2A, 8.2C, 8.2E, 8.3A, 8.3B, 8.3C, 8.3D, 8.4A, 8.4B, 8.6C, 8.9A, 8.9B, 8.9C
Unit 06: Investigating the Sun, Earth, and Moon
(12 classes for the entire unit)
This unit bundles Student Expectations that address the interactions of the Sun, Earth, and Moon system. Students use scientific practices and a variety of tools to investigate, model, and illustrate how the rotation of the Earth causes day and night and the Earth’s tilt and revolution causes changes in seasons. They demonstrate and predict the sequence of events in the lunar cycle in relationship to the positions of the Earth and Moon relative to the Sun, in addition to relating the positions of the Moon and Sun to their effect on ocean tides. Students develop the understanding that some cycles, such as day and night and phases of the Moon, are evident only by viewing them from Earth. Manipulating models enables students to correct misconceptions about these cycles. Additionally, students communicate and discuss their observations and record and organize data in their notebooks. Furthermore, students analyze and interpret information to construct reasonable explanations based on evidence from their investigations and communicate valid conclusions (supported by collected data). Students continue to demonstrate safe practices as outlined in the Texas Education Agency-approved safety standards and consider environmentally appropriate and ethical practices with resources during investigations.
TEKS in this unit: 8.2A, 8.2C, 8.2D, 8.2E, 8.3A, 8.3B, 8.3C, 8.3D, 8.4A, 8.7A, 8.7B, 8.7C
Unit 07: Investigating Components of the Universe
(14 classes for the entire unit)
Students use scientific practices and a variety of tools to investigate and describe the components of the universe, including stars, nebulae, and galaxies. They identify how different wavelengths of the electromagnetic spectrum are used to gain information about components in the universe. Students also recognize that the Sun is a medium-sized star located in a spiral arm of the Milky Way galaxy and that the Sun is many thousands of times closer than any other star. Moreover, students use the Hertzsprung-Russell diagram for classification of stars. In addition, students research how scientific data are used as evidence to develop scientific theories in order to describe the origin of the universe. Additionally, students communicate and discuss their observations and record and organize data in their notebooks. Furthermore, students analyze and interpret information to construct reasonable explanations based on evidence from their investigations and communicate valid conclusions (supported by collected data). Students continue to demonstrate safe practices as outlined in the Texas Education Agency-approved safety standards and consider environmentally appropriate and ethical practices with resources during investigations.
TEKS in this unit: 8.1A, 8.2A, 8.2C, 8.2D, 8.2E, 8.3A, 8.3B, 8.3C, 8.3D, 8.4A, 8.4B, 8.8A, 8.8B, 8.8C, 8.8D
Unit 08: Investigating Interdependence Among Living Systems
(18 classes for the entire unit)
Students use scientific practices and a variety of tools to investigate how organisms and populations in an ecosystem depend on and may compete for biotic and abiotic factors. They explore how short-term and long-term environmental changes affect organisms and traits in subsequent populations. Students recognize human dependence on ocean systems and explain how human activities have modified these systems. They realize that not all modifications to systems may have negative impacts. Additionally, students communicate and discuss their observations and record and organize data in their notebooks. Furthermore, students analyze and interpret information to construct reasonable explanations based on evidence from their investigations and communicate valid conclusions (supported by collected data). Students continue to demonstrate safe practices as outlined in the Texas Education Agency-approved safety standards and consider environmentally appropriate and ethical practices with resources during investigations.
TEKS in this unit: 8.1A, 8.1B, 8.2A, 8.2C, 8.2E, 8.3A, 8.3D, 8.4A, 8.4B, 8.11A, 8.11B, 8.11C
Unit 09: Student-Designed Investigations
(10 classes for the entire unit)
The intent of this unit is not to teach all of the process skills in isolation. Rather, it is a unit that allows students to apply the knowledge that they have obtained throughout the year in a new context that prepares them for high school science. Safety guidelines and a brief review of scientific practices should have been established at the beginning of the year, so that students are aware of protocol and how to think critically. These concepts should have been reinforced throughout the school year. Students design and implement experimental investigations testing one variable. This will involve designing a fair test in which a control is identified. This includes formulating and developing a hypothesis, writing procedures, selecting and using equipment, collecting data, analyzing and interpreting results, and communicating valid conclusions. Students may only change one variable (independent or cause) while keeping all other conditions the same. The dependent variable (effect) is observed or measured in an effort to gather evidence to support or not support a causal relationship. Furthermore, students demonstrate safe practices as outlined in the Texas Education Agency-approved safety standards and consider environmentally appropriate and ethical practices with resources during investigations.
TEKS in this unit: 8.1A, 8.1B, 8.2A, 8.2B, 8.2C, 8.2D, 8.2E, 8.3A, 8.4A, 8.4B
Texas Essential Knowledge & Skills (TEKS)
TEKS - Science - G8.pdf