Chapter 1 Test Review Flashcards
standard metric units
KHD_dcm
measuring rules
sig figs, estimated digits
what does a measurement tell you
the size of something
accuracy
“hits the target”
precision
all in one place
why is it important to communicate precision the correct way
because the more sig figs in a measurement, the more precise the measuring device
what is the general rule about the amount of precision in your answer as compared to the amount of precision in the measurements used to calculate it
you always record one unit past what the instrument records
extensive properties
depends on the amount of matter in a sample
intensive properties
depend on the type of matter in a sample, not the amount
chemical property
the ability of a substance to undergo a specific chemical change
states of matter
solid, liquid, gas, plasma
solid
definite shape and volume
liquid
indefinite shape, definite volume
gas
indefinite shape, indefinite volume
plasma
gas superheated to the point where the electrons start to leave the atoms, creating a high energy ionized gaseous substance
melting
solid to liquid
vaporization
liquid to gas
ionization
gas to plasma
freezing/fusion
liquid to solid
condensation
gas to liquid
recombination
plasma to gas
sublimation
solid to gas
deposition
gas to solid
substances
uniform and definite composition, pure, every sample has identical intensive properties
mixtures
physical blend of 2+ substances, chemical properties don’t change, varying composition
how are elements and compounds similar
any sample is the same
homogeneous mixtures
composition the same throughout, 1 phase
heterogeneous mixture
composition is not the same throughout, 2+ phases
how to separate the components of a mixture
filtration, distillation, chromatography
how to separate the components of a compound
chemical reaction
what is the ancient theory about atoms
all matter is composed of atoms, atoms aren’t dividable and are whole
what three questions did aristotle ask democritus
what holds atoms together? why can’t we see atoms? why don’t we fall down like a bag of marbles?
what did priestley work on?
he prepared pure oxygen, decomposed mercuric oxide into mercury and oxygen, discovered carbon dioxide and nitrous oxide, saw that substances can be broken down to a certain point
what did lavoisier work on
observed that substances stopped burning when cut from air/oxygen, things get heavier after burning, came up with the law of conservatoin of mass
what did proust work on
he came up with the law of definite composition, all substances are composed of definite amounts of each element no matter how much/little of the matter there is
what are dalton’s four postulates?
atoms of the same element are chemically identical; atoms of different elements can physically mix together or can chemically combine in simple whole number ratios to form compounds; chemical reactions occur when atoms are separated, joined, or rearranged; all elements are composed of indivisible particles called atoms
which of dalton’s 4 postulates does not work
all elements are composed of indivisible particles called atoms
what did thomson experiment on
he discovered that the beam of particles could be deflected by electrically charged plates
what was thomson’s model
plum pudding model (chocolate chip muffin)
what was rutherfords experiment
he directed a narrow beam of alpha particles at a thin sheet of gold foil. he figured out that atoms are mostly empty space and that a nucleus is made up of positively charged matter called protons
names of the major parts and particles of an atom
electron cloud, nucleus, electron, neutron, proton
proton mass
1 amu
proton charge
postitive
proton location
nucleus
neutron mass
1 amu
neutron charge
neutral
neutron location
nucleus
electron charge
negative
electron location
electron cloud
how do you find a mass number
protons + neutrons
what is an isotope
atoms with the normal number of protons but different number of neutrons
what is an amu
atomic mass unit, defined as one twelfth of a carbon-12 atom
what is atomic mass
its a weighted average which accounts for abundance each element occurs in nature
what is the equation for atomic mass
{mass number of isotope multiplied by (% abundance/100)}
