Filling of Atomic Orbitals and Electronic Structure

Flashcards covering the principles and rules of electron configuration including the Aufbau principle, Pauli Exclusion Principle, and Hund's Rule.

Aufbau Principle

The rule stating that in the ground state of atoms, orbitals are filled in order of their increasing energies, meaning electrons first occupy the lowest energy orbital available.

Order of orbital energies

A useful sequence for filling orbitals: $1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s...$

Potassium valence electron

The outermost electron in potassium which is found in the $4s$ orbital rather than the $3d$ orbital, as predicted by the sequence of energy levels.

Pauli Exclusion Principle

A principle given by Wolfgang Pauli (1926) stating that no two electrons in an atom can have the same set of four quantum numbers.

Wolfgang Pauli (1926)

The Austrian scientist who established that only two electrons may exist in the same orbital and they must have opposite spin.

Maximum number of electrons in a shell

A value equal to $2n^2$, where $n$ is the principal quantum number.

Subshell capacities

The maximum number of electrons allowed in orbitals: $1s$ comprises one orbital (2 electrons max), while $p$ and $d$ subshells hold a maximum of 6 and 10 electrons respectively.

Degenerate orbitals

Orbitals belonging to the same subshell that possess equal energy.

Hund’s Rule of Maximum Multiplicity

A rule that deals with the filling of electrons into orbitals belonging to the same subshell (degenerate orbitals).

Orbital Energy Determinants

Factors such as effective nuclear charge and the specific type of orbital that affect the energy level of a given orbital.