Valence electrons

Definition

Valence electrons are the outermost electrons of an atom and are involved in forming chemical bonds. They determine an element's chemical properties and reactivity.

5 Must Know Facts For Your Next Test

1. Valence electrons can be found in the highest occupied energy level (shell) of an atom.
2. Elements with the same number of valence electrons are grouped together in columns on the periodic table, known as groups or families.
3. The number of valence electrons determines whether an element will lose, gain, or share electrons in a chemical reaction.
4. Transition metals have a variable number of valence electrons because they can use their d-electrons for bonding.
5. Noble gases have a full set of valence electrons, making them mostly inert and nonreactive.

Review Questions

• How do valence electrons affect an element's position in the periodic table?
• Why are noble gases generally inert?
• What is the significance of valence electrons in chemical bonding?

Related terms

Electron Configuration: The distribution of electrons among the various atomic orbitals.

Periodic Table: A tabular arrangement of elements according to their atomic numbers, which shows patterns in their electron configurations and properties.

Chemical Bond: \text{An attractive force between atoms that enables the formation of chemical substances containing two or more atoms.}