Gr. 12 Chemistry: Quantum Mechanics

atomic thoeries, electron configuration, quantum numbers

What are the four men involved in the atomic theories?

Dalton, Thomson, Rutherford, Bohr

Dalton:

solid billiard ball - no subatomic particles

Thomson:

choc. chip muffin model - electrons like choc. chips embedded in positively charged atom

Rutherford:

nuclear model, +, tiny dense nucleus gold foil expt.

Bohr:

solar system model, electrons travel in orbits, fixed pathways around + nucleus

→ gives us the quantum number (n) principal quantum # energy level

ELECTRON CONFIGURATION:

how electrons are arranged in an atom’s shells and orbitals

AUFBAU PRINCIPAL:

lowest energy sub-level filled before moving on to the next sub-level (s<p<d<f)

PAULI EXCLUSION PRINCIPAL:

no two electrons can have the same 4 quantum numbers within an atom, they must have an opposite spin

HUND’S RULE:

spread out electrons in the same sub-level before doubling

QUANTUM NUMBERS

define an electron’s atomic orbital, including its energy level, shape, spatial orientation, intrinsic spin

The principal quantum #: