vid 6-7 hydrogen atom and many electron atoms

even though Bohr’s model is incorrect

correctly predicted radius of H atom

spin quantum number (m_s)

-1/2 or 1/2, intrinsic angular momentum of electrons only takes certain quantized directions

stern-gerlach experiment

led to spin quantum number, silver atoms deflected to either north or south pole of magnet

pauli’s exclusion principle

no two electrons can have the same four quantum numbers

how do we understand how electrons occupy orbitals

focus on effects of nuclear charge (atomic number Z) and the electrons present

which electron is easiest to remove in the 1 electron species of first three elements

in order of lowest to highest nuclear charge: H, He+, Li2+

electron shielding

for multi electron species, electrons are shielded by inner electrons → nucleus is not able to attract fully because there are others in between

effective nuclear charge (Z_eff) =

Z - S(shielding)

electrons in the same shell and electron repulsions

proton’s charge is somewhat shielded and there is repulsion between the electrons → Electron of He+ more difficult to remove than regular He

for the same shell, an electron’s penetrating power (how close it is to the nucleus) follows

s > p > d = f

order that orbitals are filled with electrons (lowest to highest energy)

1s<2s<2p<3s<3p<4s<3d<4p<5s<4d<5p<6s<4f