Periodic Table
11
Na
22.99
Sodium
Alkali MetalHighly reactive alkali metal; golden-yellow flame; stored under kerosene.
Electronic Configuration
[Ne] 3s¹or1s² 2s² 2p⁶ 3s¹
Electron shells
2e⁻n=1
8e⁻n=2
1e⁻n=3
Properties
Atomic number
11
Atomic mass
22.99 u
Category
Alkali Metal
Block / Group / Period
s · 1 · 3
Valence electrons
1
Oxidation states
+1
Electronegativity
0.93
Atomic radius
190 pm
Ionization energy
496 kJ/mol
Electron affinity
53 kJ/mol
Melting point
371 K / 98 °C
Boiling point
1156 K / 883 °C
Density
0.971 g/cm³
State at 25 °C
solid
JEE / NEET notes
- Most common alkali metal; stored under kerosene.
- Forms peroxide Na₂O₂ (pale yellow) on burning in excess O₂.
- NaHCO₃ (baking soda), Na₂CO₃·10H₂O (washing soda).
Flame test
Golden yellow (589 nm)
Ores & extraction
Ores: Rock salt (NaCl), Chile saltpetre (NaNO₃)
Extraction: Down's process — electrolysis of fused NaCl.
Uses
Na-vapour lamps · Reducing agent · Coolant in nuclear reactors · Soap (NaOH)
Important compounds
NaClNaOHNa₂CO₃Na₂O₂
Personal Notes
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