GenChem

Aufbau Principle

Aufbau Principle

• filling orbitals in order of increasing energy

• came from the word aufbauen which means build

Au (Gold)

does not follow aufbau principle

Diamagnetic

no unpaired electron ↓ (-1/2 )

Paramagnetic

has unpaired electron ↑ (1/2)

No. Types of Quantum Numbers

4

Principal quantum number

describes “shell” and “size” or orbitals

Azimuthal Quantum Number

describes the shape of the orbital

Pauli Exclusion Principle

• Filling the orbitals with two electrons in opposite spins

• like charges repel = unlike charges attract

n (definition)

• main energy level of electron

• principal quantum number

s

sublevel in the first energy level

Spin Quantum Number (ms)

describes the spin of electron (1/2 or -1/2)

Electron Configuration

representation of the arrangement of electrons

Electric Structure of Atoms

series of energy levels that are possible for a bound electron to occupy

Shell

Energy level of atom/electron

Subshell (Sublevel)

tells the shape of orbital denoted as s, p, d, f

Energy levels

• n increases = energy increases

F orbitals (Fundamental)

• seven orbitals

• known as most diffused shape

• maximum of 14 electrons

P orbitals (Principal)

• 3 orbitals

• dumbbell shape

• maximum of 6 electrons

s orbitals (sharp)

• 1 orbital

• spherical shape

• maximum of 2 electrons

D orbitals (diffused)

• 5 orbitals

• maximum of 10 electrons

Electron Configuration

arrangement of electrons within their respective sublevels

s, p, d, f table

Noble gases

• inert gases

• all ends with p⁶ configuration (except helium)

Duet rule

stable with only 2 electrons

Octet Rule

stable with 8 electrons

Noble Gas Configuration

use of noble gases in shortening the Electron Configuration

Orbital Diagram

reconstruct the electronic configuration.

Hund’s Rule of Multiplicity

All orbitals with the same energy must be filled up before pairing with another electron

Magnetic Quantum Number

shows the orientation of the orbital in space

Chemical Bonding

basic fundamental that explains other concepts such as molecules and reactions

Lewis Dot Structure

representation of valence electrons

Octet Rule

atoms tend to lose, gain, or share electrons until they have achieved an outer shell that contains an octet of electrons

Ionic Bonds

electrostatic attraction between two oppositely charged ions cause by electrons transferring from one atom to another.

Properties of Ionic Compound

• High melting and boiling point

• Conducts electricity

• Solid at room temperature

• Hard and brittle

Outermost shell

Valence Electron

Paired dots

lone pairs