New Chem/Phys Flashcards
proton
positive charge and a mass of 1 amu
neutron
no charge and mass of 1 amu
electron
negative charge and mass of 0
nuculeus
contains protons and neutrons, electrons flot around nucleus
atomic number
number of protons in a given element
mass number
sum of elements protons and neutrons
atomic mass
equal to the mass number, sum of protons and neutrons
isotopes
atoms of a given element (same atomic number) but have different mass numbers. differ in number of neiutrons
atomic weight
weighted average of the naturally occurring issues
periodic table lists these
rutherford
first said that the atom had a dense, + charged nucleus made up only a small fraction of the volume of the atom
Bohr model of an atom
dense positive charge nucleus surrounded by electrons that revolve around a nucuekus in orbit with distinct energy levels
the energy difference between levels is called a
quantum
quanitization
not an infinite range of energy levels available to an electron, electrons can exist only at certain E levels. E of an electron increases as it is farther from the nuc
atomic absorption spectrum
electron to jump from a lower E level to a higher E level, must absorb the amount of energy equal to the energy difference between the 2 levels
when electrons return from the excited state to ground state, they
emit the amount of energy that is exactly equal to the energy difference between the 2 levels. atomic emission spectrum
quantum mechanical model
electrons do not travel in defined orbits, but localized in orbitals
orbitals
a region of space around the nucleus defined by the probability of finding an electron in that region
Heisenberg uncertainty pricniple
impossible to know an electrons position and its momentum exactly at the same time
quantum numbers
n, l, m1, ms
principal quantum number
n. describes the energy of a shell.
azimuthal quantum number
l. describes the sub shells within a given principal energy level (s, p, d f, )
magnetic quantum number
m1 specifics the particular orbital within a subshell where an electron is likely to be found at a given moment in time
the spin quantum number
ms. indicates th spin ordinations with +1/2 and -1/2 of an electron in an orbital
electron confiuhration
ex. magnesium. 12 electrons
1s2, 2s2, 2p6, 3s2…
3p6, 4s2, 3d10, 4p6, 5s2, 4d10, 5p6
f has 14