Units of Matter

atom

basic unit of matter

molecule

substance that has multiple of the same atom

compound

two or more different elements

pure substance

definite and constant composition

element

a substance made of only one type of atom

mixture

two or more pure substances combined with each other

homogeneous

uniform composition, visibly indistinguishable parts

heterogeneous

composition is not uniform, multiple distinguishable parts

electrolysis

break substance into its components

vaporization

liquid to gas

freezing

liquid to solid

melting

solid to liquid

condensation

gas to liquid

sublimation

solid to gas

deposition

gas to solid

physical change

chemical identity remains the same

chemical change

chemical identity changes

corrosion

rusting

solid

definite shape, definite volume, high density, slightly compressible, molecules closely packed together

liquid

no definite shape, definite volume, mid to high density, slightly compressible, molecules slightly not packed together

gas

no definite shape, no definite volume, low density, highly compressible, molecules very far apart

plasma

ionized gas

ionization

add heat to gas

recombination

releasing heat from plasma

phase change

change from one state of matter to another

endothermic

absorb heat. melting, vaporization, sublimation

exothermic

release heat. freezing, condensation, deposition

physical property

A characteristic that does not change the chemical identity of the substance

ductile

turning a metal into metal wires

malleability

shaping something without it breaking

viscoscity

resistance of a fluid to flow

chemical property

A characteristic that will change the chemical identity of the substance

combustible

ability to explode

pH

strength of an acid