Pure Substance
Matter that always has exactly the same compositon; an element or compound.
Element
A substance that cannot be broken down into simpler substances.
Atom
The smallest particle of an element.
Compound
A substance that is made from two or more simpler substances and can be broken down into those simpler substances.
Heterogeneous Mixture
A type of mixture in which the parts of the mixture are noticeably different from one another.
Solution
A mixture that forms when substances dissolve and form a homogenous mixture.
Physical Property
Any characteristic of a material that can be observed or measured without changing the composition of the substance in the material.
Viscosity
The tendency of a liquid to keep from flowing; resistance to flowing.
Conductivity
A material's ability to allow heat or electric charges to flow.
Malleability
The ability of a solid to be hammered without shattering.
Melting Point
The temperature at which a substance changes from solid to liquid.
Boiling Point
The temperature at which a substance boils; the temperature at which vapor pressure is equal to atmospheric pressure.
Filitrartion
A process that sperates materials based on the size of their particles.
Distillation
A process that seperates the substances in a solution based on their boiling point.
Physical change
A change that occurs when some properties of a material change, but the substances in the material stay the same.
Solid
The state matter in which materials have a definite shape and definite volume.
Liquid
The state of matter in which a material has a definite volume but not a definite shape.
Gas
The state of matter in which a maerial has neither a definite shaper nor a definiite volume.
Kinetic Energy
The energy an object has due to its motion.
Pressure
The result of a force distributed over an area.
Absolute Zero
A temerature of 0 kevins.
Charlie's Law
The direct proprtion of the volume of a gas to its temperature(in kelvins) if the pressure and the number of particles of the gas are constant.
Boyle's Law
The inverse variation of the volume of a gas with its pressure if the temperature and the number of particles are constant.
Phase Change
A reversible physical change that occurs when a substance changes from one state of matter to another.
Endothermic
A description of a change in which a system absorbs energy from its surroundings.
Heat of Fusion
The energy a substance must absorb in order to change from a solid to a liquid.
Exothermic
A description of a change in which a system releases energy to its surroundings.
Vaporization
The phase change in which a substance changes from a liquid into a gas.
Heat of Vaporization
The energy of a substance must absorb in order to change from a liquid to a gas.
Evaporation
The process that changes a substance from a liquid to a gas at temperature below the substance's boiling point.
Vapor Pressure
The pressure caused by the collisions of particles in a vapor with the walls of a contanier.
Condensation
The phase change in which a substance changes from a gas or vapor to a liquid.
Sublimation
The phase change in which a substance changes from a solid to a gas or vapor without chaging to a liquid first.
Deposition
The phase change in which a gas or vapor changes directly into a solid without first changing into a liquid.