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Unit 8 Vocabulary
Term | Definition |
---|---|
Kinetic Theory | An explanation of how the particles in gases behave |
Solid | - Least amount of energy - Energy is vibrational and rotational - Define shape and volume |
Crystalline Solid | - Particles have specific geometric arrangements - Definite melting and boiling points |
Amorphous Solid | - No specific melting point - Gradually turn to liquid over wide temp. range - Lack crystal structure |
Liquid | - More energy than a solid - Particles can slide past each other (flow) - Vibrational, Rotational, and Translational energy - Define volume, but no definite shape |
Liquid Crystals | Substances that keep their geometric arrangement when changing from a solid to a liquid, but can lose the arrangement when heated or electrified |
LCD | Liquid Crystal Display |
Gas | - More energy than solids and liquids - No definite volume or shape - Large spaces between particles |
Plasma | Gas-like mixture of positively and negatively charged particles |
Thermal Expansion | Increase in the size of a substance when the temperature is increased |
Boiling | - Occurs when vapor pressure equals atmospheric pressure - Requires more energy - All particles involved |
Evaporation | - Occurs only at the surface - Requires less energy - Occurs at any temp. and pressure |
Heat of Fusion | The energy required to change a substance from solid to liquid at its melting point |
Heat of Vaporization | The amount of energy required for a liquid at its boiling point to become a gas |
Fluid | A substance without a fixed shape |
Buoyant Force | Upward force exerted by a fluid on an object immersed in or floating on the fluid |
Archimede's Principle | The buoyant force on an object is equal to the weight of the fluid displaced by the object |
Pressure | Force exerted per unit area |
Pascal's Principle | Pressure applied to a fluid is transmitted throughout the fluid |
Venturi Effect | Narrowing a stream of fluid increases the speed of the fluid |
Bernoulli's Principle | When the velocity of a stream of fluid increases, the pressure exerted by the fluid decreases |
Viscosity | The resistance of a fluid to flowing |
Boyle's Law | Pressure and volume have an inverse relationship when temperature is held constant |
Charle's Law | The temperature and volume of a gas have a direct relationship when pressure is held constant |
Gay-Lussac Law | The pressure and temperature of a gas have a direct relationship when volume is held constant |
Matter | Anything that has mass and takes up space |
Substance | Type of matter with a fixed composition |
Element | A substance made of atoms that are all alike |
Compound | Substance in which the atoms of two or more elements are chemically combined in a fixed proportion |
Mixture | Matter composed of two or more substances that can be separated by physical means |
Heterogeneous Mixture | Mixture in which different materials remain distinct |
Homogeneous Mixture | Mixture that remains constantly and uniformly mixed and has particles that are so small they cannot be seen with a microscope |
Suspension | Heterogeneous mixture made of large particles that settle |
Colloid | Heterogeneous mixture with particles that never settle |
Tyndall Effect | The scattering of a light beam as it passes through a colloid or suspension |
Solution | Another name for a homogeneous mixture Alloy = solid mixture |
Physical Property | Any characteristic of a material that you can observe without changing the identity of the substance |
Physical change | A change in size, shape, or state, of matter in which the identity of the substance remains the same |
Distillation | Process of separating substances in a mixture by evaporating a liquid and recondensing its vapor |
Chemical Property | Any characteristic of a material that you can observe that produces one or more new substances |
Chemical Change | A change of one substance to another |
Indicators | Bubbles, release of energy, solids produced in a liquid |
Law of Conservation of Mass | The mass of all substances present before a chemical change equals the mass of all substances that remain after the change |