Quantum Mechanical Wave Model

Louis de Broglie

Showed that electrons can be thought as a wave of energy instead of a particle

Heisenberg Uncertainty Principle

Basically stated that its impossible to know both exact momentum & location of an electron

Bc electrons are so small & charged, any beam of light used to find it would MOVE it!

De Broglie + Heisenberg

We cannot know where an electron is. So instead of attempting to find the exact location, we get to know the probability of finding an electron in a specific region of space called orbitals

Principle Quantum Number (LEVEL / N)

• whole numbers (n= 1,2,3,4)

• relates to distance the electron is from the nucleus

• tells us energy level

What are the 4 quantum numbers that are assigned to electrons?

n, l, ml, ms

Secondary Quantum Number (SECTION/L)

• Defines shape of the orbital

• # of values is determined by the value ‘n’

• for each value of ‘n’, l= 0,1,2…-1

• each value of l is designed by a letter: s,p,d,f

• L=0 means s orbital, sphere

• L=1 means p orbital, dumbbell/hourglass

• L=2 means d orbital, double dumbbell

• L=3 means f orbital

Magnetic Quantum Number (ROW/ml)

• orientation in space of the orbital

• splits subshells into individual orbits

• an orbital fan hold 2 electrons total

• It may hold 0,1, or 2 but never more than 2

Magnetic Spin (SEAT/ms)

Indicates orientation of the electrons in each orbital

• +1/2 or -1/2

• Electrons can soin clockwise or counterclockwise

• 2 electrons in any orbital MUST have OPPOSITE spins

• The number of electrons in a shell is 2n²

Aufbau principle

When adding electrons to an atom, lower energy orbits must be filled first

Pauli’s exclusion principle

Atomic orbital can ONLY have 2 electrons and they must have opposite spins

Hund’s rule

When we have degenerate orbitals (orbitals w same energy) then each orbital is filled with single electron before being doubly occupied