Atomic and Electronic Structure

Heisenberg’s Uncertainty Principle

it is impossible to know both the exact locaation and momentum of an electron at the same time

Quantum Numbers

set of four numbers that describes the movement and energy of an electron in an atom

Principle quantum number (n)

the energy level that the electron resides in (how far in it is from the nucleus)

• must be greater than or equal to 1

maximum number of electrons is…

2n²

Angular Momentum Quantum number (l)

describes the orbital shape → can be between 0 and (n - 1)

if l = 0…

the orbital is s - subshell

if l = 1

the orbital is p - subshell

if l = 2

the orbital is d - subshell

When l = 3…

the orbital is f - subshell

Magnetic Quantum number (m_l)

describes the orbital orientation in space → ranges between +l and -l

• if l = 1 → p-subshell

• l = 1 → m_l = -1, 0, +1

spin quantum number (m_s)

describes spin angular momentum

• m_s = +1/2 or -1/2

Pauli Exclusion Principle

no two electron within an atom can have the exact same set of quantum numbers

Hund’s rule

all degenerate orbitals will be singly occupied before any are doubly occupied

Electron configuration

describes the number of electrons in each orbital and the order in which subshells are filled in an atom

Exceptions to the Aufbau Procedure - Chromium

the 4s electron goes to the 3d, so it has two half filled shells

Exceptions to the Aufbau Procedure - Copper

you end up getting a half filled 4s and full 3d, its stabilizing to either have half filled or fully filled shells.

Isoelectronic Species

species that have the same electron configuration