12. Electron-electron Interaction Flashcards
State what the ludicrously independent electron approximation says
All electrons go into the lowest energy 1s single electron state
State what is wrong with the ludicrously independent electron approximation
Not allowed as electrons are fermions and cannot occupy the same state
How many electrons can fit into the 1s state and why?
2 - spin up and down.
Write this as 1s^2
State what the ridicuously independent electron approximation says
- Electrons fill up the single electron state according to the PEP. These states are identical to the states of the single electron ion
- Should be some Coulomb repulsion, and their wave functions overlap
- Each electron has a unique set of quantum numbers
- States filled up from the lowest energy
How many sub shells does each n shell have?
2l + 1
What does Hund’s first rule state?
Spins prefer to be aligned than anti aligned
See page 5 of document for Hund’s 1st rule
do it lol
Briefly describe the positions of the electrons for the symmetric and anti symetric states
Further apart for anti-symmetric states - reduced Coulomb repulsion
What can be said about binding energy for the symmetric and anti symmetric states
Slightly higher for symmetric spin states
Define ionisation energy
The smallest amount of energy required to remove an electron from the atom
(or smallest binding energy)
Define screened potential
Electrons moving in an effective CENTRAL potential, but it accounts for other electrons in the same approximate way
What can be said about the force an electron feels in an outer shell compared to the inner ones w.r.t the nucleus?
It is less i.e it doesn’t feel the full Coulomb attraction of the Z protons
Define screening
Inner shells “screen” nuclear charge for outer shell electrons
See page 6 of document for screened potential sketch
do it lol
How does the screened potential behave for large and small r?
Small r - “sees” full nuclear charge
Large r - “sees” less of the net charge
