Quantum-Mechanical Model

pg. 294-301

LO: I can write the electron configuration of elements in the PT.

What is the quantum-mechanical model?

A model that explains...The probability of where an electron exists

when orbiting the nucleus.

With a focus on...The energy of the electrons

Bohr Model vs. Quantum-Mechanical Model

Bohr

Orbits—circular path around the nucleus showing the electrons motion.

Differently sized radii

Quantum-Mechanical

Orbitals—probability map showing likelihood of where an electron will be found.

Differently sized shapes

Quantum Numbers

• Used to specify an electron’s “address”• 4 total numbers

1. Energy level “n”2. Sublevel “shape”3. Orientation of sublevel orbitals4. Spin of electrons in sublevel orbitals “ms”

QN1: Energy Levels

1. Energy level “n” n = 1, 2, 3, 4, 5, 6, 7The higher the number, the

farther the e- is from the nucleus.

QN2: Sublevel Shape

2. Sublevel “shape” s = spherical p = lobed d = dumbbell f = “complicated”

There are as many sublevels as the number of the level.

QN3: Orientation

3. Orientation of sublevel s = 1 orientation p = 3 orientations d = 5 orientations f = 7 orientations

QN4: Electron Spin

4. Electron Spin “ms” s = p = d = f =

Hund’s Rule: Electrons occupy sublevels one at a time before filling up with a second electron.

Pos. Spin= Neg. spin=

Electron Configurations (addresses)

Electron Configuration: Tells us the location of an electron in the electron cloud.

Pauli Exclusion Principle: No two electrons have the same configuration (address).

Aufbau Principle: Electrons will occupy the lowest energy position (sublevel) available. (like tennis balls filling a tube)

Aufbau Principle: How orbitals are filled

Complete the half-sheet and insert it into your ISN

Electron Configuration ExamplesProcess

1. Determine the # of electrons

2. Fill up electrons in each energy sublevel

Lowest Highest 3. Don’t forget

Hund’s RuleHW: Worksheet write the first 20 element electron

configurations due (Monday 11/16)