Lewis Dot Symbols

In-depth explanation of Lewis Dot Symbols

A Lewis dot symbol shows an element's chemical symbol surrounded by dots representing its valence electrons. Electrons are placed one per side first on the four sides of the symbol and only then paired, so that unpaired dots remain visible. The number of unpaired dots indicates how many bonds the atom can typically form in a covalent compound. The notation is a bookkeeping tool that makes clear which electrons take part in bonding and which remain as lone pairs. For main-group elements the group number gives the valence electron count directly.

Going deeper: Lewis Dot Symbols

Key ideas: Write the dots by group: groups 1, 2 give 1 and 2 dots, group 13 gives 3, 14 gives 4, and so on up to 8 for group 18. For transition metals the symbol is rarely used. For ions, add or remove dots and write brackets with the charge, such as Cl with eight dots and a minus sign for chloride.

Common mistakes and connections: Typical errors are pairing dots before each side has one, and drawing the dots of a cation as though the lost electrons were still there. For Na+ the symbol shows no dots at all, as the outer shell is now the filled 2p shell. Connects to the octet rule, Lewis structures and periodic groups.

Visualization of Lewis Dot Symbols

Nitrogen has two core electrons and five valence electrons in its outer shell. Its Lewis symbol shows those five as dots: one pair and three single electrons. The interactive lesson shows this as a live animation or chart.

Worked example and use case

Nitrogen in group 15 has five valence dots, one pair and three single electrons, so it usually forms three bonds.

Where Lewis Dot Symbols fits in Bonding & Molecular Structure

Lewis Dot Symbols is topic 7 of 104 in Bonding & Molecular Structure.

Related topics

• Ionic BondBeginner
• Covalent BondBeginner
• Metallic BondBeginner
• Lewis StructuresBeginner
• Single Double and Triple BondsBeginner
• Lone PairsBeginner

Browse all 104 topics in Bonding & Molecular Structure