Electron Configuration Overview

Flashcards covering key concepts in electron configuration, principles guiding electron arrangement, and notable exceptions in electron configurations.

Electron Configuration

The arrangement of electrons in an atom, which tends to give the atom the lowest energy possible.

Ground State

The lowest energy state of an atom.

Aufbau Principle

Each electron occupies the lowest energy orbital available, filling from lowest to highest energy levels.

Pauli's Exclusion Principle

No two electrons in an atom can have the same four quantum numbers; electrons in the same orbital must have opposite spins.

Hund's Rule

Electrons fill a subshell singly before forming pairs, and each electron in a singly occupied orbital has the same spin.

Orbital Diagram

A visual representation showing the arrangement of electrons in orbitals.

Electron Configuration Notation

A method of writing the distribution of electrons in subshells using superscripts to indicate the number of electrons.

Copper Exception

Copper has the electron configuration [Ar] 4s¹3d¹⁰ instead of [Ar] 4s²3d⁹ due to lower energy in a filled d orbital.

Chromium Exception

Chromium has the electron configuration [Ar] 4s¹3d⁵ instead of [Ar] 4s²3d⁴, for similar reasons related to stability.

Atomic Number

The number of protons in the nucleus of an atom, which is equal to the number of electrons in a neutral atom.