241 terms

8th Grade Science

Vocabulary set based on Washington State Standards and Performance Expectations.
STUDY
PLAY
Adaptation
The ability of a species to survive in a particular environment because of alterations of form or behavior brought about through natural selection.
Analyze
To examine carefully and in detail so as to identify causes, key factors and possible results.
Anatomy
The structure of an animal or plant, or of any of its parts.
Apply
The skill of selecting and using information in new situations or problems.
Asexual reproduction
Involves one parent and leads to offspring that are genetically identical to the parent and to one another.
Asteroid
Small rocky body orbiting the Sun, sometimes called minor planet or planetoid.
Atmosphere
The layer of gases that may surround the Earth and other material bodies of sufficient mass.
Atoms
The basic unit of matter consisting of a dense central nucleus surrounded by a cloud of negatively charged electrons.
Attributes
A characteristic of a thing.
Average
The mean obtained by adding several quantities together and dividing the sum by the number of quantities.
Average speed
The measure of distance that an object travels in a given time period.
Bar Graph
Used to illustrate comparative data such as cost, birth rates, etc. by using parallel bars of varying lengths.
Biodiversity
The diversity among and within plant and animal species in an environment.
Boiling point
The temperature at which a liquid becomes a gas. The boiling point changes as pressure changes.
Catastrophe
A sudden and widespread disaster as a result of a violent disturbance.
Cells
The basic unit of all living organisms found in both plants and animals, having a nucleus and surrounded by a very thin membrane.
Cell Membrane
The semipermeable membrane enclosing the cytoplasm of a cell.
Cell Wall
The rigid boundary or wall made of cellulose that is part of the outer structure of a plant cell.
Change of state or phase
A change from one state (solid or liquid or gas) to another without a change in chemical composition.
Characteristic
A distinguishable trait, quality, or property.
Characteristic of Life
In order for something to be considered living, it must be made of one or more cells, have organization, use energy, live in stable conditions, grow and reproduce.
Chemical change
The altering of an object's chemical composition (changing what it is made of).
Chemical Energy
Energy liberated by a chemical reaction or absorbed in the formation of a chemical compound.
Chemical properties
Any of a material's properties, such as color, pH, boiling point, melting point, density, or it's ability to react with another material.
Chemical (change) reaction
A process in which atoms rearrange themselves to form a new substance.
Chloroplast
An organelle found in plant cells that's function is to carry out photosynthesis.
Chromosome
Circular strand of DNA that contains the hereditary information necessary for cell life.
Circulatory System
The system of organs and tissues, including the heart, blood, blood vessels, involved in circulating blood through the body.
Classification key
A method to group and categorize species of organisms.
Classify
To arrange in some sort of order by categories or groupings.
Climate
Includes the temperatures, humidity, atmospheric pressure, winds, rainfall, atmospheric particle count, and numerous other meteorological elements in a given region over long periods of time.
Closed system
A system in which matter may circulate, but may not enter or leave.
Comet
A small Solar System body that orbits the Sun and, when close enough to the Sun, exhibits a visible tail made of gas and/or dust.
Compare
To examine two or more objects or events to establish similarities.
Composition
The makeup of a material. A material formed from two or more substances.
Compound
A substance consisting of two or more different elements chemically bonded together.
Concept
The general notion or idea.
Concept map
A visual representation of concepts in a figure, using boxes, arrows, and other symbols to help show relationships between different items. It is a graphical tool for organizing and representing knowledge.
Conclusion
A final statement of the findings of an investigative process that is supported by investigative evidence (data).
Condensation
the process of changing a gas or vapor to a liquid.
Conduction
The transfer of heat energy through matter by the movement of molecules.
Conductor
A substance, body, or device that readily conducts heat, electricity, sound, etc.
Conservation of Mass (energy)
A physical law stating that the total amount of mass remains constant. Also stated as: mass can be neither created nor destroyed during a chemical reaction—only rearranged.
Consumer
An organism that gets its chemical energy for growth and development from other organisms. Animals in a food web are consumers that obtain food energy by eating other animals or plants.
Contrast
To examine two or more objects or events to find differences.
Control
a standard condition that other conditions can be compared to in a scientific experiment.
Controlled experiment
A laboratory investigation in which the values of all variables are kept the same except for one that is changed from trial to trial and then compared to the rest.
Controlled variables
The conditions that are kept the same from trial to trial in a laboratory investigation.
Convection
The transfer of heat energy by the physical movement of matter. Occurs in liquids and gases.
Core of the Earth
Most likely a solid sphere about 1,220 km in radius. It is believed to consist of an iron-nickel alloy.
Crust
The Earth's outermost shell that is composed of a variety of igneous, metamorphic, and sedimentary rocks. Earth's crust includes the oceanic crust, about 7-10 km thick, and the continental crust, about 35-40 km thick.
Crustal plates
Pieces of the Earth's crust that float on the asthenoshere and move in relation to one another.
Cycle
Any complete round or series of occurrences that repeats or is repeated.
Cytoplasm
The cell substance containing all the organelles outside of the nucleus and enclosed in the cell membrane.
Decomposers
Organisms that consume the remains of dead organisms and break down the tissues into simpler forms of matter that can be used as nutrients for other living organisms.
Density
Defined as mass per unit volume.
Dependent (responding) variable
The factor studied in a system that is expected to change when the manipulated (independent) variable is changed.
Deposition of sediments
The geologic process following erosion, in which particles of sand or soil are no longer transported from their source by wind or water and are added to a new landform.
Describe
The skill of developing a detailed picture, image or characterization using diagrams and/or words, written or oral.
Design
To prepare the plans for work to be executed, such as preparing steps to take to complete a lab.
Diagram
A chart, plan or drawing that outlines and explains the parts or operation of something.
Digestive System
The system by which ingested food is acted upon by physical and chemical means to provide the body with absorbable nutrients and to excrete waste products.
Distance
The amount of space between two points usually measured by length in metric or standard units.
Dissolve
To make a solution of by mixing with a liquid.
Diversity
A wide variety. Species diversity refers to the abundance of different species within an ecosystem.
DNA
The large molecules inside the nucleus of living cells that carry genetic information.
Draw
To deduce or infer.
Dwarf planet
A body gravitationally bound to the Sun with enough mass to be approximately spherical in shape, but not enough mass to have pulled in debris from the neighborhood of their orbit.
Earthquake
A series of vibrations induced in the earth's crust by the abrupt rupture and rebound of rocks in which elastic strain has been slowly accumulating.
Eclipse
An astronomical event that occurs when one celestial object moves into the shadow of another.
Ecosystem
A natural unit consisting of all plants, animals, and microorganisms in an area functioning together with all of the nonliving physical factors of the environment.
Effect
The result or consequence of an action, influence, or causal agent.
Electrical Energy
Energy made available by the flow of electric charge through a conductor.
Electron
A particle of an atom that carries a negative charge.
Element
A pure chemical substance composed of all atoms that have the same number of protons.
Energy
The amount of work that can be done by a force.
Energy transfer
The movement of energy from one location to another.
Energy transformation
The change of energy from one form to another.
Environment
The natural surrounding that includes living and nonliving components. May also refer to a region or to all natural systems on planet Earth.
Erosion
When solids (sediment, soil, rock and other particles) are carried away or displaced usually by wind, water, or ice by down-slope movement in response to gravity or by living organisms.
Estimate
To form an approximate judgment or opinion regarding the worth, amount, size, weight, etc., of; calculate approximately.
Evaluate
To make judgments based on collected data.
Evaporation
Change in state of a substance from liquid to gas.
Evidence
Tends to prove or disprove something by making observations and measurements, or collecting data through scientific processes.
Evolution
The change in the gene pool through a series of gradual or rapid changes of a population from generation to generation by such processes as mutation, natural selection, and genetic drift accounting for the current diversity of species.
Experiment
A test, trial, or tentative procedure with the purpose of discovering something unknown.
Explain
To apply scientific ideas to describe the cause of a phenomenon or relationship and/or to render a complex idea plain.
External
The outside or outer part of a surface.
Extinction
The death of all members of a species of plant or animal. It is generally considered to be the death of the last individual of that species, although the capacity to breed and recover may have been lost before this point.
Factor
The agent or condition that could cause a change.
Fault
A geological rock fracture that shows evidence of relative Earth movement that may extend hundreds or even thousands of kilometers.
Feedback
The process by which the output of a system is used to make changes in the operation of the system.
Field studies
The scientific study of free-living plants or animals in which the subjects are observed in their natural habitat without changing, harming, or materially altering the setting or subjects of the investigation.
Food web
The complex eating relationships among species within an ecosystem. Organisms are connected to the organisms they consume by arrows representing the direction of energy transfer.
Force
A push or pull that has both magnitude and direction.
Formation
The act or process in which a thing is formed or arranged.
Fossils
The preserved remains or traces of animals, plants, and other organisms from the remote past.
Friction
The force that acts to slow or stop the motion of objects.
Galaxy
A collection of stars, gas, and dust bound together by gravity and isolated from similar systems by vast regions of space.
Gas
A state of matter consisting of a collection of particles without a definite shape or volume that are in more or less random motion.
Gene
A segment of inheritance information that specifies a trait.
Genetic
Something inherited or affected by genes.
Genetic information
A set of instructions coded in DNA molecules that specifies the traits of an organism.
Genetic variation
A measure of the tendency of individual genotypes in a population to vary from one to another.
Gravity
The force by which any two masses are attracted to one another and governs the motion of the Solar System.
Habitat
An ecological or environmental area that is inhabited by a particular species. It is the natural environment in which an organism lives or the physical environment that surrounds (influences and is used by) a species population.
Heat
A form of kinetic energy produced by the motion of atoms and molecules and may be transferred from one body or system to another due to a difference in temperature.
Heat Transfer
The process in which heat moves from one body or substance to another by radiation, conduction, convection, or a combination of these methods.
Heredity
The passing of traits to offspring. This is the process by which an offspring cell or organism acquires the characteristics of its parent cell or organism.
Hydrologic Cycle
(Also called Water Cycle) The natural sequence through which water passes into the atmosphere as water vapor, precipitates to earth in liquid or solid form, and ultimately returns to the atmosphere through evaporation.
Hydrosphere
The water on or surrounding the surface of the globe, including the water of the oceans and the water in the atmosphere.
Hypothesis
A testable explanation for a specific problem or question based on what has already been learned.
Igneous rock
Formed when molten magma cools.
Independent (manipulated) variable
The factor of a system being investigated that is changed to determine that factor's relationship to the dependent (responding) variable.
Infer
To arrive at a decision or logical conclusion by reasoning from evidence.
Inference
A logical conclusion based on evidence.
Input
the addition of matter, energy, or information to a system.
Inquiry
The diverse ways in which people study the natural world and propose explanations based on evidence derived from their work.
Insulator
A material that is a poor conductor of energy such as electricity or heat.
Internal
The inside or inner part of the body or part.
Interpret
To present an explanation of an event or process.
Intrinsic
Anatomy. (of certain muscles, nerves, etc.) belonging to or lying within a given part.
Investigate
To plan and conduct an organized scientific study to answer a question.
Investigation
A method of planning or conducting a scientific study to answer a question or problem
Kinetic energy
The energy of motion.
Landform
A specific geomorphic feature on the surface of the earth, ranging from large-scale features such as plains, plateaus, and mountains to minor features such as hills, valleys, and alluvial fans.
Law
An observed regularity of the natural world that scientists have observed repeatedly and can be used to accurately predict what will happen in many situations.
Line Graphs
Visual representations made by connecting data points of successive changes in the value of a variable quantity.
Lithosphere
The solid portion that is made up of the crust and upper mantle of the earth.
Liquid
A fluid that takes the shape of the part of the container that it occupies, and that forms a distinct surface.
Logical argument
A set of one or more assumptions supported by evidence that leads to a clear conclusion.
Lunar Eclipse
When the Earth comes between the sun and the moon. When the moon is in the Earth's shadow it is not visible, so the moon is blocked by the Earth.
Magnetism
The properties of attraction possessed by magnets; the molecular properties common to magnets.
Manipulated (independent) variable
The factor of a system being investigated that is changed to determine that factor's relationship to the dependent (responding) variable.
Mantle
A thick, putty-like layer between the crust and the outer core that is about 2,900 km thick and makes up about 70% of Earth's volume.
Mass
A measure of how much matter there is in an object.
Matter
Anything that has mass and that takes up space.
Mean
The average obtained by adding several quantities together and dividing the sum by the number of quantities.
Measure
The act or process to determine the extent, dimension, quantity or length of something.
Melting point
The temperature at which a solid melts and becomes a liquid.
Metamorphic rock
Rocks modified by temperatures and pressures that are high enough to change the original minerals into other mineral types or into other forms of the same minerals.
Milky Way Galaxy
The galaxy containing the solar system; consists of millions of stars that can be seen as a diffuse band of light stretching across the night sky.
Mitochondria
The organelle in the cytoplasm that functions in energy production.
Mixture
A substance made by combining two or more different materials without a chemical reaction occurring because the objects do not bond together.
Models
A simplified representation of a system and are useful for studying systems that are too big, too small, or too dangerous to study directly.
Molecule
A stable unit of two or more atoms held together by chemical bonds.
Moons
A natural satellite that is a celestial body that orbits a planet or smaller planetary body.
Motion
A constant change in the location of an object.
Multicellular
Composed of several or many cells.
Natural selection
The process by which heritable traits that are favored by environmental conditions become more common in successive generations, and heritable traits that are less favored by environmental conditions become less common. Over time, this process may result in the emergence of new species.
Neutron
A particle of an atom that carries a neutral charge.
Niche
The position of a species or population in its ecosystem. A shorthand definition of niche is how and where an organism makes a living.
Nucleus (In physics)
The central structure in an atom that contains neutrons and protons.
Nucleus (In biology)
The central structure in a living cell enclosed in a membrane that includes most of the genetic information in the cell that controls growth and reproduction in most living things.
Nutrients
A food or chemicals that an organism needs to live and grow, or a substance used in an organism's metabolism that must be taken in from its environment.
Observation
The skill of recognizing and noting some fact or occurrence in the natural world using the senses.
Open system
A system in which matter may flow in and out, as opposed to a closed system in which matter may not flow in or out.
Orbit
The gravitationally curved path of one object around a point or another body.
Organ
A group of tissues in plants or animals that perform a particular task.
Organelle
"Little organs." Small specialized cell parts that carry out functions within the cell.
Organ system
A group of organs that work together to perform a particular task.
Organism
A living thing such as an animal, plant, fungus, or microorganism.
Output
Matter, energy, or information that flows out of a system.
Patterns
Recurring events or objects that repeat in a predictable manner.
Phase
Any of the forms or states in which matter can exist, depending on temperature or pressure.
Phase Change
The metamorphosis of a material or mixture from one phase to another such as gas to liquid or solid to gas.
Phases of the Moon
Can be explained by its changing relative position as it orbits Earth.
Phenomena
A fact, occurrence, or circumstance observed.
Photosynthesis
A metabolic pathway that converts light energy into chemical energy. Its initial substrates are carbon dioxide and water; the energy source is sunlight (electromagnetic radiation); and the end products are oxygen and (energy-containing) carbohydrates, such as sucrose, glucose, or starch.
Physical change
Any change not involving modification of a substance's chemical identity, such as a change of state from solid to liquid, a change in appearance or a change is size or color.
Physical Property
Any property used to characterize matter and energy and their interactions most often observed by using the senses.
Planet
A round object that has its own orbit around a star, such as the sun.
Plate Tectonics
The theory that lithospheric plates move slowly over the underlying mantle.
Plutoid
A dwarf planet outside the orbit of Neptune.
Population
The collection organisms of a particular species that can breed and reproduce.
Precipitation
A form of water, such as rain, snow, or sleet, that condenses from the atmosphere, becomes too heavy to remain suspended, and falls to the Earth's surface.
Predict
Use prior knowledge to guess what will happen.
Pressure
The exertion of force upon a surface by an object, fluid, etc.
Principle
Rule or law concerning the functioning of systems of the natural world.
Problem
A question or circumstance which can be solved using a scientific study or investigation.
Procedure
An organized series of steps to conduct a scientific investigation.
Producer
An organism that produces complex organic compounds from simple inorganic molecules using energy from light or inorganic chemical reactions.
Properties
Essential attributes shared by all members of a group.
Proton
A particle of an atom located inside the nucleus that carries a positive charge.
Question
A problem for discussion or under discussion.
Radiation
Energy in the form of rapidly propagating waves or particles emitted by a body as it changes from a higher energy state to a lower energy state.
Reactant
Any substance that undergoes a chemical change in a given reaction.
Relationship
Connections observed among systems, subsystems, or variables.
Reproduction
The natural process among organisms by which new individuals are generated and the species perpetuated.
Research
Gathering of information for the study of an idea or a scientific problem.
Respiratory System
The system for taking in oxygen and giving off carbon dioxide.
Responding (dependent) variable
The factor of a system being investigated that changes in response to the manipulated (independent) variable and is measured.
Ribosome
A cell organelle constructed in the nucleus. It consists of two subunits and functions as the site of protein synthesis in the cytoplasm.
Rock Cycle
A model that describes how rocks slowly change from one form to another through time.
Sample
To take a sample of, especially to test or examine by a sample.
Satellite
An object that orbits a planet or moon.
Sediment
Any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of water or other liquid.
Sedimentary rock
Rocks formed by deposition of solid particles at the bottom of a body of water, followed by compaction and cementation. Common sedimentary rocks include shale, sandstone, and limestone.
Sexual reproduction
The production of new generations involving the combination of chromosomes from both a male and female parent. Because each parent contributes genetic information, the offspring of sexual reproduction are usually not identical to either parent.
Simulation
Imitation or enactment, as of something anticipated or in testing.
Skepticism
The attitude in scientific thinking that emphasizes that no fact or principle can be known with complete certainty; the tenet that all knowledge is uncertain.
Solar Eclipse
When the Moon comes between the sun and the Earth, so that a viewer is in the moon's shadow, blocking the view of the sun.
Solar System
The Sun and those celestial objects bound to it by gravity, including eight planets, moons, dwarf planets, plutoids, asteroids, meteoroids, and other small bodies.
Solid
The state of matter characterized by resistance to deformation and changes of volume.
Solubility
The ability of a given substance to dissolve in a liquid.
Solute
A substance which is dissolved within a solution.
Solvent
A substance, usually a liquid, capable of dissolving another substance.
Solution (process)
A device or process created through technological design to meet a human need or want.
Solution (physical science)
A mixture in which particles of one substance are evenly distributed through another substance.
Species
A group of organisms capable of interbreeding and producing fertile offspring.
Speed
The rate or measure of the rate of motion. The distance travel divided by the time of travel.
States of matter
Matter can exist in various states (or forms), which may depend on temperature and pressure. Traditionally, three states of matter are recognized: solid, which maintains a fixed volume and shape; liquid, which maintains a fixed volume but adopts the shape of its container; and gas, which occupies the entire volume available. Plasma, or ionized gas, is a fourth state that occurs at very high temperatures.
Sublimation
a change in state or phase whereby a substance moves from solid to gas phase without going through liquid phase.
Substance
That of which a thing consists; physical matter or material.
Survey
Examine and record the area and features of an area of land so as to construct a map, plan, or description.
System
An assemblage of interrelated parts or conditions through which matter, energy, and information flow.
Technology
Ways that people change the natural world to solve practical problems or improve the quality of life.
Theory
An integrated, comprehensive explanation of many facts capable of generating hypotheses and testable predictions about the natural world.
Theory of Evolution
Explains the facts of biological evolution in terms of the law of natural selection and the facts and laws of genetics. Scientists use this theory to explain how the current diversity of living things came into existence and the relationships between modern organisms and their more "primitive" ancestors.
Thermal
Pertaining to heat.
Thermal Energy
The movement of atoms and molecules in matter. It is a form of kinetic energy produced from the random movements of those molecules. Thermal energy of a system can be increased or decreased.
Tissue
A group or layer of cells that are alike and work together to perform a specific function.
Trait
A distinguishing characteristic or quality.
Transfer
Move from one place to another.
Transform
Change from one form to another.
Trials
Repetitions of data collection protocols in an investigation.
Tsunami
Unusually large waves created when a body of water, such as an ocean, is rapidly displaced by an earthquake, volcanic eruption, landslide, or other disruption (plural: tsunami).
Unbalanced Forces
When acted upon an object, it changes the speed or direction of an object's motion.
Unicellular Organism
Having or consisting of a single cell.
Validity
Measuring what you claim to be measuring through tightly controlled conditions with an emphasis on quality by checking and questioning the observations or data and discussing their accuracy.
Variable
Any changed or changing factor used to test a hypothesis or prediction in an investigation that could affect the results.
Variation
A measure of the tendency of individuals in a population to differ from one another.
Visible Light
Electromagnetic radiation to which the organs of sight react, ranging in wavelength from about 400 to 700 nm, considered variously as a wave.
Volume
The amount of the three-dimensional space enclosed within or occupied by an object, geometric solid, etc.
Water cycle
Continuous cycle of water molecules on Earth as they rise into the atmosphere, fall back to Earth as rain or other precipitation, and flow into rivers or oceans.
Water vapor
The gas phase of water.
Wave
A disturbance that propagates through space and time, usually with transference of energy. Examples of wavelike phenomena are light, water waves, and sound waves.
Wavelength
The distance between one peak or crest of a wave and the next peak or crest. It is equal to the speed of the wave divided by its frequency, and to the speed of a wave times its period.
Weathering
The decomposition of earth rocks, soils and their minerals through direct contact with the planet's atmosphere or biological agents.
Weight
The strength of the gravitational pull on an object.
Wind
The flow of air or other gases that compose an atmosphere.