Wave Mechanical Model
Although the Bohr-Rutherford Model could explain the line spectrum for hydrogen, it could do so for other elements.
It also wrongly suggested that the electron was a particle whose exact position and velocity could be specified at any time.
Instead, we do know the probability of finding an electron in a place at a certain time.
Wave Mechanical Model
Electrons occupy certain energy levels/shells in an atom. The number of electrons in each level is
Instead of 2-D orbits, electrons are found in 3-D orbitals (electron clouds, sublevels, subshells) Each orbital defined an area where the probability of finding an electron is high. Each orbital is classified by some shape, and contains a maximum of 2 electrons.
s - 1 path
p - 3 paths
d - 5 paths
f - 7 paths
Electrons can spin clockwise or counter-clockwise, meaning each path can have 2 electrons.
For example, the third level has
Periodic Table Groupings
Getting the Final Configuration Term
Where:
is the row or period of the atom - Note that transition metals are offset up by 1
is the block that the atom belongs to - Left block + helium is the
sblock - Transition metals is the
dblock - Right block is the
pblock - Bottom block is the
fblock
- Left block + helium is the
is the column relative to the atoms block
Rules
- Hund's Rule
- "Seats on a school bus"
- Everyone want's their own "seat" and when all the "seats" are full then electrons start to double up
- Formal definition: assign each orbital 1 electron before doubling up
- Pauli exclusion principle
- Each orbital only has 2 electrons spinning in opposite directions
- Aufbau Principle
- "Building up"
- Electrons are added to the lowest energy orbital available
Ion Charges
The s and p electrons are considered more likely t; participate in chemical bonding