Substances and Mixtures
What is an element and a compound?
Element: a substance made up of atoms that are all alike
Compound: a substance in which two atoms or more elements are chemically combined in a fized proportion
What is bouyancy?
The ability of a fluid, a liquid, or a gas to exert an upward force on an object immersed in it.
What is a physical property, and what is a chemical property.
Physical Property:Any characteristic of a material that you can observe without changing the identity of the substance.
Chemical Property: Any characteristic of a material that you can observe and produces on or more new substances.
What is the law of conservation mass?
Law that states that the mass of all substances that are present before a chemical change, the reactants, equals the mass of all the substances that remain after the change.
What is the Kinetic Theory and what is Kinetic Energy.
Kinetic Theory: the explanation of how the particles in gases behave.
Kinetic Energy: energy of motion
What is a homogenous and heterogenous mixture.
Homogenous: A mixture that remain constantly and uniformly mixed
Heterogenous A mixture in which different materials look distinct
What is bouyant force?
Buoyant force is the upward force a fluid exerts on an object.
What is a physical change and what is a chemical change?
Physical Change:A change in size, shape, or state of matter in which the identity of the substance remains the same.
Chemical Change: A change of one substance to another.
What is Archimede's Principle?
The buoyant force on an object is equal to the eight of the fluid displaced by the object.
What is Thermal Energy and what is Temperature?
Thermal Energy: the total energy of a material’s particles
Temperature: how hot or cold an object is
What is a colloid and what is the Tyndall effect
Colloid: a heterogenous mixture with particles that bever settle
Tyndall effect: the scattering of a light beam as it passes through a colloid
What is pressure?
The force exerted per unit area.
List 3 physical properties and 3 chemical properties.
Physical Properties: Color, size, shape
Chemical Properties: Flammability, toxicity, heat of combustion.
What is Pascal's Principle?
The pressure applied to a fluid is transmitted throughout the fluid.
State which is which:
Solid to liquid, liquid to gas, gas to liquid, solid to gas
Melting: solid to liquid:
Condensation: gas to liquid
Vaporization: liquid to gas
Sublimation: solid to gas
What is a substance and a mixture
Substance: A pure substance that has a fixed composition. Can be an element or a compound
Mixture: Matter composed of two or more substances that can be separated by physical means.
What is viscosity?
The resistance of a fluid to flowing.
3 clues that indicate a Chemical Change has occured, and 3 clues that a Physical change has occured.
Chemical: Odor change, color change, and release of energy.
Physical: Shape, size or state of matter.
What is Bernoulli's Principle?
Fluid velocity increases when the flow of the fluid is restricted.
What is heat of vaporization, melting point and heat of fusion?
HEAT OF VAPORIZATION: the amount of energy required for a liquid at its boiling point to become a gas
HEAT OF FUSION: the energy required to change a substance from solid to liquid at its melting point
MELTING POINT: the temperature at which a solid becomes a liquid
What is a suspension?
a heterogeneous mixture made of solid and liquid particles
What is Boyle's Law and Charle's Law?
Charle's: The volume of a gas increases with increasing temperature, as long as the pressure on the gas does not change. If you take a ball outside on a cold day, the ball shrinks a bit as the temperature is decreased.
Boyle's: If you decrease the volume of a container of gas and hold the temperature constant, the pressure from the gas will increase. When air is blown into the balloon the pressure of that air pushes on the rubber, making the balloon expand.
What is weathering?
When Earth’s surface undergoes chemical and physical changes.