Sodium (Na) - Element 11 | Properties & Electron Configuration
What is Sodium?
Sodium (Na) is element 11, a alkali metal in period 3, group 1. Its electron configuration is 1s² 2s² 2p⁶ 3s¹.
| Atomic Number | 11 |
| Symbol | Na |
| Atomic Mass | 22.99 u |
| Category | Alkali Metal |
| Period | 3 |
| Group | 1 |
| Block | s |
| Electron Configuration | 1s² 2s² 2p⁶ 3s¹ |
| Short Config | [Ne] 3s¹ |
| Electronegativity | 0.93 |
| Atomic Radius | 180 pm |
| Ionization Energy | 496 kJ/mol |
| Electron Affinity | 53 kJ/mol |
| Phase (STP) | Solid |
Electron Configuration
The full electron configuration of Sodium is 1s² 2s² 2p⁶ 3s¹. In noble gas shorthand, this is written as [Ne] 3s¹.
Sodium is a s-block element in group 1, period 3.
Periodic Trends
Electronegativity: Sodium has a Pauling electronegativity of 0.93. Within group 1, electronegativity generally decreases down the group.
Atomic Radius: 180 pm. Across period 3, atomic radius generally decreases left to right as nuclear charge increases.
Ionization Energy: 496 kJ/mol. Ionization energy generally increases across a period and decreases down a group.
View all 118 elements with trend overlays for electronegativity, atomic radius, ionization energy, and electron affinity.
Explore Sodium on the Interactive Periodic TableRelated Topics
Hydrogen (H)
Properties of Hydrogen - same group as Sodium
Lithium (Li)
Properties of Lithium - same group as Sodium
Potassium (K)
Properties of Potassium - same group as Sodium
Magnesium (Mg)
Properties of Magnesium - same period as Sodium
Aluminum (Al)
Properties of Aluminum - same period as Sodium
Silicon (Si)
Properties of Silicon - same period as Sodium