Summary of "Electron Configuration - Quick Review!"

Main Ideas and Concepts

Electron Configuration Basics
Each element has a specific number of electrons equal to its atomic number. The Electron Configuration describes the distribution of electrons among the various orbitals.
Writing Electron Configurations
The order of filling orbitals follows the Aufbau principle, which states that electrons fill lower-energy orbitals before higher-energy ones.

The maximum capacity for each type of orbital is:
- S: 2 electrons
- P: 6 electrons
- D: 10 electrons
Ground state electron configurations can be represented in two ways: standard notation and noble gas notation.
Orbital Diagrams
Orbital Diagrams visually represent the arrangement of electrons in orbitals. According to Hund's rule, electrons must fill degenerate orbitals singly before pairing up.
Ions and Electron Configurations
The Electron Configuration for ions is adjusted based on the charge: for a negative ion, add electrons; for a positive ion, remove electrons from the highest energy level first.
Valence and Core Electrons
Valence Electrons are those in the outermost energy level and are important for chemical reactivity. Core electrons are those in inner shells and do not participate in bonding.
Paramagnetism and Diamagnetism
A substance is paramagnetic if it has unpaired electrons and is attracted to a magnetic field. A substance is diamagnetic if it has all paired electrons and is weakly repelled by a magnetic field.
Exceptions in Electron Configurations
Some elements, like Chromium and copper, have exceptions in their electron configurations where electrons can shift from the s to the d orbitals to achieve a more stable configuration.

Methodology and Instructions

Writing Electron Configuration for Sulfur
Atomic number: 16 (16 electrons)

Configuration: 1s² 2s² 2p⁶ 3s² 3p⁴

Noble gas notation: [Ne] 3s² 3p⁴
Writing Electron Configuration for Sulfide Ion
Sulfide ion has 18 electrons (16 + 2).

Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶
Writing Electron Configuration for Nitrogen and Nitride Ion
Nitrogen (atomic number 7): 1s² 2s² 2p³

Nitride ion has 10 electrons: 1s² 2s² 2p⁶
Writing Electron Configuration for Aluminum and Its Ions
Aluminum (atomic number 13): 1s² 2s² 2p⁶ 3s² 3p¹

Aluminum ion (Al³⁺) has 10 electrons: 1s² 2s² 2p⁶
Writing Electron Configuration for Cobalt and Its Ions
Cobalt (atomic number 27): 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁷

Cobalt ion (Co²⁺) has 25 electrons: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁷
Exceptions for Chromium and Copper
Chromium (atomic number 24): [Ar] 4s¹ 3d⁵

Copper (atomic number 29): [Ar] 4s¹ 3d¹⁰