electron configuration

page 3-5 25/7/25 note;

electron configuration is

electron arrangement in orbitals

energy level diagram

• visual representation of levels

• s: one orbital

• p: three orbitals, p_x, p_y, p_z

• d: five orbitals

• f: ten orbitals

• s starts at 1

• p starts at 2

• d starts at 3

• f starts at 4

aufbau’s principle

fill lower energy orbitals with electrons first before moving up to higher energy orbitals

Hund’s rule

every orbital must be occupied by one electron first, before the electrons are paired up

Pauli’s exclusion principle

no electron can have the same four quantum numbers, atleast one WILL differ, double check work if not

quantum number of families on periodic table

• top to bottom

• alkali and alkaline earth metals, including helium: 1s, 2s, 3s, 4s, 5s, 6s, 7s

• transition metals: 3d, 4d, 5d, 6d

• nonmetals: 2p, 3p, 4p, 5p, 6p

• lanthanides: 4f, 5f

complete electron configuration

• will go in order of Aufbau’s principle and end at quantum number of associated spot on periodic table

• exponent indicates position on period (row)

• total sum of exponents indicates number of electrons and

condensed electron configuration

start with noble gas before element and add rest of orbitals

special stability

• when electron is promoted to next orbital

• mainly with d orbitals

• only with exponent 4 or 9

• d orbital has one electron in four orbitals and a full s orbital → one electron from s moves to empty d

• d orbital has four full orbitals, one half full, and a full s orbital → one electron from s moves to last d orbital

electron configuration for ions

• electrons do not equal protons

• add lost or gained electrons to toal

• adjust in exponents

• may be equal to another element