physical properties
can be observed without changing a substance into another substance
boiling point, density, mass, volume
examples of physical properties
boiling point, density, mass, volume
chemical properties
can only be observed when a substance is changed into another substance
example of chemical properties
flammability, corrosiveness, reactivity with acid
intensive properties
independent of the amount of the substance that is present
examples of intensive properties
density, boiling point, color
extensive properties
dependent upon the amount of the substance present
example of extensive properties
mass, volume, energy
physical changes
changes in matter that do not change the composition of a substance
examples of physical changes
change of state, temperature, volume
chemical changes
changes that result in new substances
example of chemical changes
combustion, oxidation, decomposition
dalton's postulates
concept that matter is conserved and made up of unique elemental substances formed by atoms
who discovered electron by the cathode-ray tubes
jj thompson
who measured the electron by the oil drop experiment
robert millikan
Who discovered the radioactivity?
Becquerel and the Curies
Who discovered the nucleus protons by the gold-foil experiment
ernest rutherford
Who discovered neutrons
Chadwick
atomic number
number of electrons or protons
atomic mass
number of protons + neutrons
isotopes
same element, different number of neutrons
Group 1
alkai metal
Group 2
akaline earth metal
Group 6
chalcogens
group 7
halogens
group 8
noble gas
empirical formulas
give the lowest whole number of ratio of atoms of each element in a compound
molecular formulas
give the exact number of atoms of each element in a compound
formula weight
sum of the atomic weights for the atoms in a chemical formula
molecular weight
sum of the atomic weights of the atoms in a molecule
limiting reactants
reactant present in the smallest stoichiometric amount