Question | Answer |
Dmitri Mendeleev | wrote PT on playing cards |
Democritus | atomos, properties of matter, matter is composed of atoms, atoms move through empty space |
Aristotle | empty space cannot exist, matter is made of earth fire air and water |
John Dalton | matter is composed of atoms, atoms are indivisible and indestructible, atoms of one element are different from another element, atoms combine to form compounds, Father of Modern Atomic Theory |
Sir William Cookes | cathode ray tube, discovered e- |
JJ Thompson | called e- 'corpuscles', plum pudding model |
Robert Milliken | oil drop experiment, measured the mass of an e- |
Ernest Rutherford | gold foil experiment, discovered p+ and nucleus |
James Chadwick | discovered neutron |
Neils Bohr | energy levels |
Max Plank | there is a relationship between quanta and its frequency |
Erwin Schrodinger | atomic orbitals |
Atomic number | number of protons |
Isotope | when the # of p+ does not equal the # of neutrons |
Ion | an atom with a charge as the product of either a loss or gain of an electron |
# of neutrons= | mass # - atomic # |
Mass of p+ | 1.673 x 10 (-24)g |
Mass of n | 1.675 x 10(-24)g |
Amu | atomic mass unit (1/12 C atom) |
Planetary model | by Ernest Rutherford |
Emission | giving off a photon |
Absorption spectrum | contains all wavelengths |
Crest | top of the wave |
Trough | bottom of the wave |
Frequency | how many waves per second |
Amplitude | length of the wave |
Speed of light | 3.00 x 10 to the 8th m/s |
Speed of light = wave length x frequecy | c= hf |
When the wavelength is shorter | the frequency is greater |
Octet Rule | every atom wants to have 8 valence electrons |
The Heisenberg Uncertainty Principle | it is impossible to know the velocity and position of a particle at the same time |
Aufbau Principle (Diagonal Rule) | each electron occupies the lowest energy orbital available |
Pauli Exclusion Principle | a max of 2 e- can occupy a single atomic orbital; the e- must have opposite spins |
Dalton's Atomic Theory | matter is indivisble and indestructible, atoms of an element are the same |
Hund's Rule | Single e- with the same spin must occupy each equal-energy orbital before more e- with opposite spins can occupy the same orbitals |
Ground state | lowest energy where an e- can still live |
Excited state | when an e- gains energy |
Valence e- | the e- in the outermost shell |
After the excited state | absorption of energy happens |
Atomic orbital | a regional space around the nucleus where an atom can be found |
Quantum numbers | describe the orbital |
Four quantum #s | n, l, m, s |
n | energy level where e- exist |
l | sublevels (s [sharf], p [principal], d (defuse), f [fundamental]) |
m | position on the XYZ axis |
s | spin within the orbital level |
sharf | 2 e-, spherical |
principal | 6 e-, dumb bell |
defuse | 10 e-, 5 suborbitals |
fundamental | 14 e-, 7 suborbitals |
periodic law | there is a periodic repetition of chemical and physical properties of the elements when they are arranged by increasing atomic number |
groups (families) | vertical columns |
periods | horizontal rows |
groups 1,2, and 13-18 | representative elements |
groups 3-12 | transition elements |
classifications of elements | metals, non-metals, and metalloids |
metals | good conductor of heat and electricity |
alkali metal | besides hydrogen, all the elements in group 1 |
alkaline earth metals | group 2; highly reactive |
transition elements | transition metals and inner transition metals |
inner transition metals | lanthanide series and actinide series |
nonmetals | elements that are generally gases or brittle, dull-colored solids |
group 17 | halogens, very reactive |
group 18 | noble gases, unreactive |
metalloid | has physical and chemical properties of both metals and nonmetals |
ionization energy | energy required to remove an electron from a gaseous atom |
electronegativity | the relative ability of its atoms to attract electrons in a chemical bond |