electronic structure theory, trends, and terms

the relationship between wavelength and frequency

inverse relationship;

when wavelength goes up, frequency will go down. (vice versa)

the relationship between wavelength and energy

inversely related;

when energy is small, the wavelength is long.

when energy is big, the wavelength is short.

the relationship between energy and frequency

directly proportional;

when energy is goes up, frequency goes up

electromagnectic spectrum

range of all types of electromagnetic radiation

continuous sprectrum

an unbroken series of wavelength

line spectra

the specific emission lines that come from a light emitted from a gas

emission line

consists of one wavelength of light.

ground state

when an electron is in the lowest energy orbit (n = 1)

excited state

when electrons jump up to a different energy state

how do electrons become excited

they absorb energy, as a photon.

what happens when they come back down?

they emit energy as a photon

Aufbau principle

add one electron to the subshell of lowest energy first. (to build up)

Pauli Exclusion principle

no two electrons in the same atom can have the same set of 4 quantum numbers. (they can have n, l, ml the same, but not ms)

Hund's rule

in a subshell of equal energy orbitals, electrons will occupy each orbital singly with parallel spins before pairing up.

cation

when one or more electrons are removed from an atom (a positive charged ion)

losing electron rules

main grp: (s & p) loses the electrons that were added last

transition & inner trans. metals lose thee electrons from the highest ‘n' levels first.

anion

when one or more electrons are added to an atom

rule for adding electrons

they are added in the order predicted by the Aufbau principle.

trend with atomic radius/size

across a period atomic size decreases, down a group the size increases

energy ionization energy

across a period IE increases, down a group IE decreases

exceptions for IE

between group 2 & 3

• 2 is part of the s subshell is higher than 3 since it is the beginning of the p subshell.

between group 6 & 7

• when (non-metals) in group 7 ionize (losing one electron) the repulsions of the original paired electrons are no longer there. so it makes it weaker than those in group 6.

trend for electron affinity

gets more negative across a period

exceptions in EA

• group 18 is a full subshell, therefore they have no EA

• group 2 has a fill ‘n’ s subshell, the next electron must go into the p subshell

• group 15 is a half p subshell, the next electron must pair with one of the original ones

effective nuclear charge

the pull exerted on a specific electron by the nucleus.

• depending on how far apart or close they are pulling e/o will determine the atom size.

Paragmagnetic

When there are unpaired electrons

Diamagnetic

When there are NO unpaired electrons (all of them are paired)