Ch. 6-7 Flashcards
Ionization energy (IE)
Energy needed to remove an e-
All IE values are (+)
Electron Affinity (EA)
Energy change (can be + or - ) when an atom gains an e-
Atoms release some amount of energy when gaining an e-
EA few exceptions
Noble gases: full outer energy level, e- would go into higher n value = no good
Nitrogen
Be, Mg
PES Spectrum
Graphical representation of e- configuration
Work function
Minimum energy needed to release e-
Photoelectronic effects and photons outcomes
- Nothing happened = energy of light was less than work function
- e- was ejected = energy of light was greater than work function
- any extra energy goes into kinetic energy if e-
Visible light
400-700 nm
Ground state
Lowest configuration of an e-
Ground state
Lowest configuration of an e-
Absorption
e- takes in energy and moves to a higher energy level
Excited state
An e- is in a higher energy level than normal
Emission
e- releases energy (as light that we may/may not see) and falls to a lower energy level
Energy level spacing is different for different ___
Elements
Orbitals
An area where the probability of finding an e- is high
Orbitals have a
Specific shape and energy
N =
Energy level
Aufbau principle
Electrons fill the lowest energy orbitals first
Bottom - up
Pauli exclusion principle
An orbital can hold a maximum of 2 electrons only if they have opposite spins
Hunds rule
e- will fill up degenerate orbitals as single e- before doubling up
Degenerate
Orbitals of equal energy
Ex: 3px, 3py, 3pz
Degenerate
Orbitals of equal energy
Ex: 3px, 3py, 3pz
Anions
e- are added to the highest energy level
Cations
e- are lost from highest energy level
Effective Nuclear Charge (zeff)
The actual attraction of e- to nucleus (zeff)
Particles are either attracted or repelled by one another
Degree of attraction / repulsion can be calculated
Attraction/repulsion forces between particles increase…
- When charges increases
- When distance decreases
All e- are attracted to the nucleus to some degree. Not all e- experience the full attraction to nucleus because other e- “____”
Get in the way
Atomic size depends on (in this order):
- Highest n level = electrons are located farther away from nucleus
- Zeff
- e-/e- repulsion’s
Group trends
Atomic size increases down a group because e- are located in higher energy levels = farther from nucleus
Bigger zeff = smaller
(Pull; bigger attraction = closer to nucleus)
Size decreases left to right because…
⬆️zeff = ⬆️ attraction = ⬆️ pull = ⬇️ closer to nucleus (smaller)
Anions
(-) ion, gain of e-
Anions are larger in size than their neutral parent atom
Cations
(+) ions, loss of e-
Cations will always be smaller in size to their neutral parent atom
Isoelectronic
Ions with the same number of e- and same e- configuration
Ionization Energy
1st IE: energy to remove e- from neutral atom
2nd IE: energy needed to remove 2nd e-
Etc.
Larger IE the harder it is to remove e-?
Huge increases in IE
Jump shows valence e-
Periodic trend
IE increases from left to right; noble gases are highest
Group trend
IE decreases as you move down a group
IE depends on 2 things:
- Zeff
- Distance from nucleus
