Quantum Numbers and Electron Configurations

These flashcards cover key terminology and concepts related to quantum numbers, electron orbitals, and configurations, assisting in the understanding of atomic structure.

Quantum Numbers

A set of four numbers that uniquely describe the location and energy of an electron in an atom.

Principle Quantum Number (n)

Defines the size and energy of the orbital; integer values greater than zero.

Angular Momentum Quantum Number (ℓ)

Defines the shape of the orbital; takes values from 0 to n-1.

Magnetic Quantum Number (mℓ)

Defines the orientation of the orbital; takes integer values from -ℓ to +ℓ.

Spin Quantum Number (ms)

Indicates the spin direction of an electron; value is +½ (spin up) or -½ (spin down).

s Orbitals

Spherical electron orbitals; one s-orbital exists for each energy level.

p Orbitals

Two-lobed orbitals centered at the nucleus; three p-orbitals for each energy level, designated as px, py, pz.

d Orbitals

Complex shapes; five d-orbitals exist for each energy level, including cloverleaf shapes.

f Orbitals

Complex shapes without simple representations; seven f-orbitals exist for each energy level.

Aufbau Principle

Electrons occupy the lowest energy orbitals available before filling higher energy orbitals.

Hund's Rule

Electrons fill degenerate orbitals singly first before pairing up.

Pauli Exclusion Principle

No two electrons in the same orbital can have the same spin; an orbital can hold a maximum of two electrons.

Klechowski's Rule

The order of filling orbitals based on increasing energy.

Electron Configuration

Representation of the distribution of electrons in an atom's orbitals.

Valence Electrons

Electrons in the outermost shell that participate in chemical reactions.

Degenerate Orbitals

Orbitals that have the same energy level.