Science Flashcards 9th Grade Vocab Terms.

Analyze To separate into basic parts; to evaluate results of an experiment. Closed system A system in which matter may not enter or leave. Conclusion A statement of the findings of an experiment that is supported by scientific evidence (data). Controlled variable The conditions that are kept the same from trial to trial in a scientific investigation. Responding variable The factor of a system being investigated that changes in response to the independent (manipulated) variable. Hypothesis A testable prediction for a specific problem or question based on what has already been learned. Independent (maniuplated) variable The factor of a system or experiment that is changed to determine its relationship to the dependent (responding) variable. Model A simplified representation of a system. Useful for studying systems that are too big, too small, or too dangerous to study directly. Subsystem A smaller group of interrelated parts within a larger system. System A group of interrelated parts or conditions through which matter, energy, and information flow. Boiling point The temperature at which a liquid changes state and becomes a gas. Characteristic Propertiy A distinguishable trait, quality, or property. Chemical reaction A process that results in the conversion of chemical substances (reactants) to other substances (products). Products generally have different chemical properties from the reactants. Condensation The change of the physical state of matter from a gas to a liquid. Gas A state of matter consisting of a collection of particles without a definite shape or volume. Liquid A form of matter that takes the shape of its container and has a definite volume. Melting point The temperature at which a solid becomes a liquid. Physical change Any change of a substance that is reversible, such as a change of state from solid to liquid, or liquid to gas. Solubility The ability of a given substance to dissolve in a liquid. Solution A mixture in which particles of one substance are evenly distributed through another substance. Adaptation Any change in the structure or functioning of an organism that is favored by natural selection and makes the organism better suited to its environment. Atmosphere A layer of gases that surrounds the Earth and other planets. Condution The transfer of heat energy a warmer substance to a cooler substance through direct contact Convection The physical movement of molecules within fluids (e.g. liquids and gases); one of the major modes of heat transfer. Eclipse An astronomical event that occurs when one celestial object moves into the shadow of another. Ecosystem A natural unit consisting of all planets, animals, and microorganisms (biotic factors) in an area functioning together with all of the nonliving physical (abiotic) factors of the environment. Fault In geology a rock fracture that shows evidence of relative Earth movement. Some may extend hundreds or even thousands of kilometers. Organism A living thing such as an animal, plant, fungus, or microorganism. Capable of reacting to stimuli, reproduction, growth, and maintenance as a stable whole. Producer An organism that makes its own food. Solar System The Sun and those celestial objects bound to it by gravity, including eight planets, moons, dwarf planets, plutoid, asteroid, meteoroids, and other small bodies. Atom The smallest unit of matter consisting of a dense central nucleus surrounded by a cloud of negatively charged electrons. Compound A substance consisting of two or more different elements chemically bonded together. Conservation of Mass A physical law stating that the total amount of mass isn a closed system remains constant. Also stated as: mass can be neither created nor destroyed- only rearranged. Decompose To break down into simpler forms of matter Density Mass per unit volume Element A pure chemical substance composed of the same type of atom. Gravity The force of attraction between two objects Mass A measure of the amount of matter in an object Proton A positively charged particle located in the nucleus of an atom. Weight The strength of the gravitational pull on an object. Accelerate Change in velocity over time. The rate at which sometimes speeds up or slows down. Conservation of Energy A physical law stating that the total amount of energy in a closed system remains constant. Also stated as energy cannot be created or destroyed- only changed from one form to another. Energy The ability to do work Energy transformation Change of energy from one form to another. Force A push or pull. (In physics, it is whatever can cause an object with mas to accelerate. Has both magnitude and direction, making it a vector quantity.) Frictional force The force acting in the opposite direction of motion. Heat The transfer of thermal energy between substances Matter Anything that has mass and that takes us space. Speed The rate of motion; the distance traveled divded by the time of travel. Temperature An average measure of how quickly the particles of matter are moving in a substance.