Electron configuration

Definition

Electron configuration describes the distribution of electrons in an atom's orbitals. It is crucial for understanding chemical bonding and properties.

5 Must Know Facts For Your Next Test

1. Electrons fill orbitals starting with the lowest energy level first, following the Aufbau principle.
2. The Pauli exclusion principle states that no two electrons in an atom can have the same set of quantum numbers.
3. Hund's rule dictates that electrons will fill degenerate orbitals singly before pairing up.
4. Electron configurations can be abbreviated using noble gas notation to simplify longer configurations.
5. Valence electrons, found in an atom's outermost shell, play a key role in determining its chemical reactivity.

Review Questions

• What principle states that no two electrons can have the same set of quantum numbers?
• How does Hund's rule affect the way electrons fill orbitals?
• Why are valence electrons important in determining chemical reactivity?

Related terms

Orbital: A region of space around the nucleus where an electron is likely to be found.

Quantum Numbers: Numbers that describe the properties and location of an electron within an atom.

Valence Electrons: Electrons located in the outermost shell of an atom that participate in chemical bonding.