Lithium (Li)

Silvery-white metal

Lithium is the lightest metal, soft enough to cut with a knife and buoyant enough to float on water, and with a single 2s¹ valence electron, lithium is highly reactive and forms strong ionic bonds. It is the lightest solid element (0.534 g/cm³) and is used in rechargeable batteries and psychiatric medication.

Key metrics

Density0.534g/cm³

Melting point453.7K

Boiling point1,603K

Electronegativity0.98Pauling

Discovery

1817discovered

Discovered by: Johan August Arfwedson
Reactivity profile: Highly Reactive Metal
Reactivity: High
Bonding: Metallic

Electron configuration

\textcolor{#6b7280}{[He]}\; \textcolor{#ef4444}{2_{s}^{1}}

[He] 2s1

Wave function

\Psi_{\text{Li}} \approx \frac{1}{\sqrt{3!}} \det \left| \chi_1(\mathbf{r}_1) \dots \chi_3(\mathbf{r}_3) \right|

Probability density $|\Psi|^2$ across the Li 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: 167 pm
Ionization energy: 520 kJ/mol
Electron affinity: 59.6 kJ/mol
Crystal structure: Body-centered cubic (bcc)

Oxidation states

Acid/base

Basic

Strongly acidicStrongly basic

State at 25 °CSolid

453.7 K1603 K298 K

Emission spectrum

3 transitions

380450500550600650700780

VioletBlueGreenYellowRed

460.3nmLi IBlue20%

610.4nmLi IOrange40%

670.8nmLi I (red)Red100%

Dominant line 670.8 nmRange 460–671 nmTransitions 3