Electron Configuration and Quantum Numbers

These flashcards cover key vocabulary related to electron configurations and quantum mechanics based on lecture notes.

Heisenberg Uncertainty Principle

It states that complementary variables (like position and momentum) cannot both be accurately known at the same time.

Planck's Constant

A fundamental constant used to describe the sizes of quanta in quantum mechanics.

Wave-Mechanical Model

A quantum model of the atom which describes electrons as matter waves and incorporates the Heisenberg Uncertainty Principle.

Wavefunction (Ψ)

A mathematical function that describes the quantum state of a particle and encodes its wave-like behavior.

Quantum Numbers

A set of numbers that describe the energy levels and shapes of orbitals where electrons may be found.

Pauli Exclusion Principle

No two electrons in an atom can have the same set of four quantum numbers.

Hund's Rule

Electrons will occupy degenerate orbitals singly before pairing up to minimize repulsion.

Aufbau Principle

The principle that electrons fill orbitals starting from the lowest energy level to the highest.

Degenerate Orbitals

Orbitals that have the same energy level.

Orbital Penetration

The extent to which an electron wave function spreads out in the region near the nucleus.

Effective Nuclear Charge (Z_eff)

The net positive charge experienced by an electron in a multi-electron atom.

Valence Electrons

Electrons in the outermost shell of an atom which are involved in chemical bonding.

Core Electrons

Electrons that are in the inner shells and are not involved in bonding.

Octet Rule

Atoms tend to gain, lose, or share electrons to have a full outer shell of eight electrons.

Electron Shielding

The phenomenon where inner shell electrons reduce the effective nuclear charge felt by outer shell electrons.

Quantum Number n

Denotes the principal energy level of an electron in an atom.

Quantum Number ℓ

Denotes the shape of the orbital.

Quantum Number mℓ

Denotes the orientation of the orbital in space.

Quantum Number ms

Denotes the spin of the electron within an orbital.