 Matter- anything that has mass and volume  Atom- smallest unit of an element that keeps the properties of element  Element- pure substance made of only one type of atom  Compound- substance made of 2 or more types of atoms that are chemically bonded  Molecule- type of compound in which bonds are covalent bonds

Particles of matter are ALWAYS in motion. The kinetic energy (speed) of these particles increases as temperature increases.

 chemists use characteristic properties to tell substances apart and to separate them  some properties define a group of substances

 Extensive- depend on the amount of matter  Ex: volume, mass, amount of energy  Intensive- do not depend on the amount  Ex: density, boiling point, ability to conduct

 Physical- characteristics that can be observed or measured without changing the identity of a substance  Chemical- relates to a substances ability to undergo changes that transform it into a different substance  Easiest to see when a chemical is reacting

 definite volume  definite shape  Particles are rigidly held in fixed positions  strong attractive forces between atoms  only vibrate in place

 definite volume  indefinite shape  atoms are close together  atoms can overcome attractive forces to flow

 indefinite volume  indefinite shape  atoms move very quickly  atoms are far apart  pretty weak attractive forces  high compressibility

MATTER Can it be physically separated? Homogeneous Mixture (solution) Heterogeneous MixtureCompoundElement MIXTUREPURE SUBSTANCE yesno Can it be chemically decomposed? noyes Is the composition uniform? noyes ColloidsSuspensions

 Element composed of identical atoms EX: copper wire, aluminum foil

 Compound composed of 2 or more elements in a fixed ratio properties differ from those of individual elements EX: table salt (NaCl)

 Law of Definite Composition A given compound always contains the same, fixed ratio of elements.  Law of Multiple Proportions Elements can combine in different ratios to form different compounds.

 For example… Two different compounds, each has a definite composition.

 Variable combination of 2 or more pure substances. HeterogeneousHomogeneous

 Solution homogeneous very small particles no Tyndall effect Tyndall Effect  particles don’t settle  EX: rubbing alcohol

 Examples: graphite pepper sugar (sucrose) paint soda element hetero. mixture compound hetero. mixture solution

 Colloid heterogeneous medium-sized particles Tyndall effect particles don’t settle EX: milk

 Suspension heterogeneous large particles Tyndall effect particles settle EX: fresh-squeezed lemonade

 Examples: mayonnaise muddy water fog saltwater Italian salad dressing colloid suspension colloid solution suspension