Where is the Electron Located?

The Quantum Model of the Atom

Heisenberg uncertainty principle: It is impossible to determine both the position and velocity of an electron or any other particle

What is the Address of the Electron?

Principle Quantum Number (n): Indicates the energy level occupied by an electron.

Angular Momentum (l): Indicates the shape of the orbital (s,p,d,f,g)

Atomic Numbers and Quantum Numbers

Magnetic Quantum Number (m): Indicates the orientation of an orbital around the nucleus.

Spin Quantum Number (↓↑): Indicates which way the electron is spinning

What are the Rules Governing Electron Configuration?

Aufbau Principle: An electron occupies the lowest energy orbital available

Pauli Exclusion Principle: Only two electrons per orbital and they must spin in opposite directions

Hund’s Rule: Each orbital of equal energy must have one electron before a second electron is added

Let’s Fill Up The Orbitals!

Summary of Orbitals

Principle Quantum #

Sublevels Number of Orbitals

Number of Electrons

1 s 1 2

2 s, p 3 8

3 s, p, d 5 18

4 s, p, d, f 7 32

Predicting the 1s Orbital

Exceptions to Aufbau