chemistry test 2- classification of matter Flashcards
matter
-anything that has mass and volume
volume
-the amount of three dimensional space an object occupies
mass
-a measure of the amount of matter
atom
-the smallest unit of an element
-maintains the chemical identity of that element
element
-pure substance
-cannot be broken down into simpler stable substances
-made of one type of atom
kinetic molecular theory
-all matter is made of particles that are always moving
-all particles have space between them
-all particles have energy
-more space = more energy
-temperature is a measure of kinetic energy of the particles
-as temp is changed, change in state may occur
-attractive forces between particles are stronger as particles are closer together
temperature
-a measure of the average kinetic energy of particles
-a change in temp could result in a change in state
solid (characteristics)
-definite shape and volume
-particles packed close together
-particles vibrate
-very strong attractive forces, low energy
liquid (characteristics)
-definite volume, no definite shape
-particles are close together but can slide past one another
-particles flow
-strong attractive forces, medium energy
gas (characteristics)
-no definite shape or volume
-particles are as spread out as possible
-particles move with great speed
-attractive forces are very weak, very high energy
pure substance
-has a fixed compostion
-composed of just one type of particle (atom or molecule)
-can either be compounds or elements
compound
-pure substance
-two or more elements combined through a chemical reaction
-composed of a definite group of molecules or ions that are chemically bonded
mixture
-a physical combination of two or more substances
-identities and properties of the individual substances are retained
-can be separated by physical means
compound vs. mixture
-compound have a definite composition (formula)
-mixtures do not have a definite composition
genos
kind
heterogeneous
-does not appear to be the same throughout
-particles are large enough to see and separate the mixture
-not uniform
-ex. oil and water
homogeneous
-appears to be the same throughout
-particles do not settle out when left standing
-also called a solution
ex. saltwater
filtration
-passing a mixture through a porous material to separate one substance from another
-uses the physical property of size
evaporation
-ex. saltwater- water evaporates and leaves salt behind
-uses the physical property of vaporization point (boiling)
distillation
-separation of liquid mixtures
-liquid with the lowest boiling point will vaporize first
-collect vapor that is then condensed and collected as a pure liquid
-uses the physical property of vaporization point
decanting
-separation by pouting off the liquid layer and leaving solids behind
-uses the physical property of state of matter
-liquids are fluid and solubility
chromatography
-separating components of a mixture based on attraction
-ex. hydrophobic
evaporation vs. distillation
-both use vaporization point to separate mixture
-evaporation is more concerned with the solid left behind
-distillation is more concerned with the pure liquid that is vaporized
particles
-pieces of matter
-atoms, molecules, or ions
