Chemical Elements - Sodium (Na)[Bohr Model of Sodium], Number of Energy Levels: 3. First Energy Level: 2. Second Energy Level: 8. Third Energy Level: 1.chemical symbol for sodium,Chemical formula for sodium - ChemicalformulaSodium has a low density which is less than water and is very soft. You can cut sodium with a knife. The chemical formula of sodium is Na. The symbol is derived.