11 Na 22.99

Sodium

alkali metal

Properties

Atomic number
11
Atomic mass
22.99 u
Category
alkali metal
Group
1
Period
3
Block
s-block
State (room temp)
Solid
Outer-shell electrons
1
Electronegativity
0.93 (Pauling)
Density
0.968 g/cm³
Melting point
97.79 °C
Boiling point
882.94 °C

Electron configuration

1s² 2s² 2p⁶ 3s¹

Noble-gas shorthand: [Ne] 3s¹

Electrons per shell: 2, 8, 1 — that's 1 in the outermost shell.

See how electron configuration is built →

Na
Bohr model — outer-shell electrons in blue

About Sodium

Sodium /ˈsoʊdiəm/ is a chemical element with symbol Na (from Ancient Greek Νάτριο) and atomic number 11. It is a soft, silver-white, highly reactive metal. In the Periodic table it is in column 1 (alkali metals), and shares with the other six elements in that column that it has a single electron in its outer shell, which it readily donates, creating a positively charged atom - a cation.

Position in the periodic table

Open the interactive periodic table →

Data compiled from Wikipedia, PubChem, and IUPAC. Source.