Sodium (Na)

Silvery-white metal

Sodium is a soft, silvery Alkali that reacts violently with water and air, and its single 3s¹ valence electron gives it a low ionization energy, making it extremely reactive. It plays a vital role in biological processes such as nerve transmission and fluid balance through the Na⁺/K⁺ ATPase pump.

Key metrics

Density0.971g/cm³

Melting point370.9K

Boiling point1,156K

Electronegativity0.93Pauling

Discovery

1807discovered

Discovered by: Humphry Davy
Reactivity profile: Violently Reactive with Water
Reactivity: High
Bonding: Metallic

Electron configuration

\textcolor{#6b7280}{[Ne]}\; \textcolor{#ef4444}{3_{s}^{1}}

[Ne] 3s1

Wave function

\Psi_{\text{Na}} \approx \frac{1}{\sqrt{11!}} \det \left| \chi_1(\mathbf{r}_1) \dots \chi_{11}(\mathbf{r}_{11}) \right|

Probability density $|\Psi|^2$ across the Na valence shell.

Crystal structure

Body-Centered Cubic

Lattice constantsa = 1.00

Cell anglesα = β = γ = 90°

Coordination number8

Atoms per cell2

Atomic packing factor0.68

Physical properties

Atomic radius: 186 pm
Ionization energy: 496 kJ/mol
Electron affinity: 52.8 kJ/mol
Crystal structure: Body-centered cubic (bcc)

Oxidation states

Acid/base

Basic

Strongly acidicStrongly basic

State at 25 °CSolid

370.9 K1156 K298 K

Emission spectrum

4 transitions

380450500550600650700780

VioletBlueGreenYellowRed

568.3nmNa IYellow30%

589.0nmNa I D2Yellow100%

589.6nmNa I D1Yellow100%

818.3nmNa I (IR)IR40%

Dominant line 589.6 nmRange 568–818 nmTransitions 4