chemistry chapter 2
matter
anything that has mass and take up space
chemistry
the study of the compositon of matter and the changes it undergoes
solid- characteristics- 6
definite shape, definite volume, stationary( vibrate and rotate), organized, particles are close, incompressable
liquid characteristics- 6
indefinite shape (shape of container), definite volume, particles are relatively close together, not organized (flows), particles move from place to place, imcompressible
gas characterisitcs 6
indefinite shape, indefinite volume, particles are very far apart, particles move, not organized, compressible
vapor
a substance now in the gas phase usually thought of as a solid of liquid
extensive property
characteristics that depend on the amount of matter present
intensive property
characteristics that depend on the type of matter instead of the amount of matter (identity)
examples of an extensive property 4
volume, energy, width, weight
example of an intensive property 5
boiling point, freezing point, color, density, texture
physical change
to modify the appearance of matter without changing its identity
ex of physical change 7
freezing, melting, bending, tearing, cutting, denting, evaporation,
ex of reversible physical changes
freezing, melting, denting, evaporation
ex of irreversible physical change 2
breaking, tearing
chemical change
to modify the identity of a substance or substances
ex of chemical change
leaves changing color, camp fire, spolied food
mixture
a physical blend between two or more substances that do not chemically react
heterogeneous mixture
a blend of matter which is a clear mix between two or more substances
homogeneous mixture
a blend of matter that looks uniform in its composition
solution
homogeneous mixture
phase
any part of a heterogeneous mixture that has uniform composition and properties
filtration
a process that generally separates a solid from a liquid using a semi permeable layer
ex filtration
spagetti and water, fruit and water, sifting sand, lemon squeezing
distillation
a liquid is boiled away from a mixture and then recondensed to recollect the liquid
pure substance
matter that has uniform and definite composition
difference between a pure substance and a mixture
a pure substance has a definite composition and a mixture does not
element
simplest form of matter that has a unique set of properties
compound
two or more elements that have been chemically combined
chemical symbol
a notation of one or two letters representing an element
physical property
a characteristic or measurement that can be observed without changing the substances identity
ex of physical properties
color, boiling point, texture, density
chemical property
the ability or not of a substance to undergo a specific chemical reaction
chemical reaction
the event where one or more substances change into on or more different substances
reactant
substances present before the chemical reaction
product
substances that are formed during the reaction
four observation that indicate a chemical reaction
transfer of energy, production of a gas, formation of a precipitate, color change
precipitate
a solid formed during a reaction betwee homogeneous mixtures
law of conservation of mass
matter cannot be created or destroyed
when is matter conserved during the law of conservation of mass
during a physical change or chemical reaction