8th Grade
Science

(1) Scientific and engineering practices. The student, for at least 40% of instructional time, asks questions, identifies problems, and plans and safely conducts classroom, laboratory, and field investigations to answer questions, explain phenomena, or design solutions using appropriate tools and models. The student is expected to:
   (A) ask questions and define problems based on observations or information from text, phenomena, models, or investigations;
   (B) use scientific practices to plan and conduct descriptive, comparative, and experimental investigations and use engineering practices to design solutions to problems;
   (C) use appropriate safety equipment and practices during laboratory, classroom, and field investigations as outlined in Texas Education Agency-approved safety standards;
   (D) use appropriate tools such as graduated cylinders, metric rulers, periodic tables, balances, scales, thermometers, temperature probes, laboratory ware, timing devices, pH indicators, hot plates, models, microscopes, slides, life science models, petri dishes, dissecting kits, magnets, spring scales or force sensors, tools that model wave behavior, satellite images, weather maps, hand lenses, and lab notebooks or journals;
   (E) collect quantitative data using the International System of Units (SI) and qualitative data as evidence;
   (F) construct appropriate tables, graphs, maps, and charts using repeated trials and means to organize data;
   (G) develop and use models to represent phenomena, systems, processes, or solutions to engineering problems; and
   (H) distinguish between scientific hypotheses, theories, and laws. (2) Scientific and engineering practices. The student analyzes and interprets data to derive meaning, identify features and patterns, and discover relationships or correlations to develop evidence-based arguments or evaluate designs. The student is expected to:
   (A) identify advantages and limitations of models such as their size, scale, properties, and materials;
   (B) analyze data by identifying any significant descriptive statistical features, patterns, sources of error, or limitations;
   (C) use mathematical calculations to assess quantitative relationships in data; and
   (D) evaluate experimental and engineering designs. (3) Scientific and engineering practices. The student develops evidence-based explanations and communicates findings, conclusions, and proposed solutions. The student is expected to:
   (A) develop explanations and propose solutions supported by data and models and consistent with scientific ideas, principles, and theories;
   (B) communicate explanations and solutions individually and collaboratively in a variety of settings and formats; and
   (C) engage respectfully in scientific argumentation using applied scientific explanations and empirical evidence. (4) Scientific and engineering practices. The student knows the contributions of scientists and recognizes the importance of scientific research and innovation on society. The student is expected to:
   (A) relate the impact of past and current research on scientific thought and society, including the process of science, cost-benefit analysis, and contributions of diverse scientists as related to the content;
   (B) make informed decisions by evaluating evidence from multiple appropriate sources to assess the credibility, accuracy, cost-effectiveness, and methods used; and
   (C) research and explore resources such as museums, libraries, professional organizations, private companies, online platforms, and mentors employed in a science, technology, engineering, and mathematics (STEM) field to investigate STEM careers. (5) Recurring themes and concepts. The student understands that recurring themes and concepts provide a framework for making connections across disciplines. The student is expected to:
   (A) identify and apply patterns to understand and connect scientific phenomena or to design solutions;
   (B) identify and investigate cause-and-effect relationships to explain scientific phenomena or analyze problems;
   (C) analyze how differences in scale, proportion, or quantity affect a system's structure or performance;
   (D) examine and model the parts of a system and their interdependence in the function of the system;
   (E) analyze and explain how energy flows and matter cycles through systems and how energy and matter are conserved through a variety of systems;
   (F) analyze and explain the complementary relationship between the structure and function of objects, organisms, and systems; and
   (G) analyze and explain how factors or conditions impact stability and change in objects, organisms, and systems. (6) Matter and energy. The student understands that matter can be classified according to its properties and matter is conserved in chemical changes that occur within closed systems. The student is expected to:
   (A) explain by modeling how matter is classified as elements, compounds, homogeneous mixtures, or heterogeneous mixtures;
   (B) use the periodic table to identify the atoms involved in chemical reactions;
   (C) describe the properties of cohesion, adhesion, and surface tension in water and relate to observable phenomena such as the formation of droplets, transport in plants, and insects walking on water;
   (D) compare and contrast the properties of acids and bases, including pH relative to water; and
   (E) investigate how mass is conserved in chemical reactions and relate conservation of mass to the rearrangement of atoms using chemical equations, including photosynthesis. (7) Force, motion, and energy. The student understands the relationship between force and motion within systems. The student is expected to:
   (A) calculate and analyze how the acceleration of an object is dependent upon the net force acting on the object and the mass of the object using Newton's Second Law of Motion; and
   (B) investigate and describe how Newton's three laws of motion act simultaneously within systems such as in vehicle restraints, sports activities, amusement park rides, Earth's tectonic activities, and rocket launches. (8) Force, motion, and energy. The student knows how energy is transferred through waves. The student is expected to:
   (A) compare the characteristics of amplitude, frequency, and wavelength in transverse waves, including the electromagnetic spectrum; and
   (B) explain the use of electromagnetic waves in applications such as radiation therapy, wireless technologies, fiber optics, microwaves, ultraviolet sterilization, astronomical observations, and X-rays. (9) Earth and space. The student describes the characteristics of the universe and the relative scale of its components. The student is expected to:
   (A) describe the life cycle of stars and compare and classify stars using the Hertzsprung-Russell diagram;
   (B) categorize galaxies as spiral, elliptical, and irregular and locate Earth's solar system within the Milky Way galaxy; and
   (C) research and analyze scientific data used as evidence to develop scientific theories that describe the origin of the universe. (10) Earth and space. The student knows that interactions between Earth, ocean, and weather systems impact climate. The student is expected to:
   (A) describe how energy from the Sun, hydrosphere, and atmosphere interact and influence weather and climate;
   (B) identify global patterns of atmospheric movement and how they influence local weather; and
   (C) describe the interactions between ocean currents and air masses that produce tropical cyclones, including typhoons and hurricanes. (11) Earth and space. The student knows that natural events and human activity can impact global climate. The student is expected to:
   (A) use scientific evidence to describe how natural events, including volcanic eruptions, meteor impacts, abrupt changes in ocean currents, and the release and absorption of greenhouse gases influence climate;
   (B) use scientific evidence to describe how human activities, including the release of greenhouse gases, deforestation, and urbanization, can influence climate; and
   (C) describe the carbon cycle. (12) Organisms and environments. The student understands stability and change in populations and ecosystems. The student is expected to:
   (A) explain how disruptions such as population changes, natural disasters, and human intervention impact the transfer of energy in food webs in ecosystems;
   (B) describe how primary and secondary ecological succession affect populations and species diversity after ecosystems are disrupted by natural events or human activity; and
   (C) describe how biodiversity contributes to the stability and sustainability of an ecosystem and the health of the organisms within the ecosystem. (13) Organisms and environments. The student knows how cell functions support the health of an organism and how adaptation and variation relate to survival. The student is expected to:
   (A) identify the function of the cell membrane, cell wall, nucleus, ribosomes, cytoplasm, mitochondria, chloroplasts, and vacuoles in plant or animal cells;
   (B) describe the function of genes within chromosomes in determining inherited traits of offspring; and
   (C) describe how variations of traits within a population lead to structural, behavioral, and physiological adaptations that influence the likelihood of survival and reproductive success of a species over generations.