---
title: "Lithium (Li): Atomic Mass, Electron Configuration & Properties"
url: https://www.moldraw.com/elements/lithium.html
description: "Lithium (Li), element 3: atomic mass 6.94, electron configuration [He] 2s¹, group 1, period 2, s-block alkali metal. Melting and boiling point, density, electronegativity and shells."
lang: en
publisher: Scidart Academy
generated: 2026-11-03
---
3Li6.94

# Lithium (Li) – element 3

Lithium is a chemical element with the symbol **Li** and atomic number **3**. It is a alkali metal in group 1 (alkali metals), period 2 of the periodic table (s-block), and is a solid at room temperature.

Lithium (Li) has atomic number 3, atomic mass 6.94 u and electron configuration [He] 2s1.

[Download periodic table PDF](https://www.moldraw.com/printables/periodic-table.pdf)[Open interactive periodic table](https://www.moldraw.com/tools/free-chem-tools/interactive-periodic-table.html)

## Lithium facts

| Symbol | Li |
| --- | --- |
| Atomic number | 3 |
| Atomic mass | 6.94 u (g/mol) |
| Category | alkali metal |
| Group | group 1 (alkali metals) |
| Period | 2 |
| Block | s-block |
| Phase at 20 °C | Solid |
| Electron configuration | 1s2 2s1 |
| Noble-gas notation | [He] 2s1 |
| Electrons per shell | 2, 1 |
| Valence electrons | 1 |

## Bohr model and shells

Lithium has 3 electrons in 2 shells: 2, 1. Full configuration and noble-gas notation are in the table; work out any element or ion with the [electron configuration calculator](https://www.moldraw.com/tools/free-chem-tools/electron-configuration-calculator.html).

## Physical and atomic properties

| Melting point | 453.65 K (180.5 °C) |
| --- | --- |
| Boiling point | 1603 K (1329.8 °C) |
| Density | 0.534 g/cm³ |
| Electronegativity (Pauling) | 0.98 |
| Electron affinity | 59.6326 kJ/mol |
| Ionization energies | 520.2, 7298.1, 11815 kJ/mol (1st, 2nd, 3rd) |
| Molar heat capacity | 24.86 J/(mol·K) |
| Discovered by | Johan August Arfwedson |

Use the atomic mass in the [molar mass calculator](https://www.moldraw.com/tools/free-chem-tools/molar-mass-calculator.html) for any formula containing Li.

## Position in the periodic table

Tap any element to open its page.

## Frequently asked questions

### What is the atomic mass of lithium?

The atomic mass of lithium is 6.94 u, so one mole of lithium atoms weighs 6.94 g.

### What is the electron configuration of lithium?

Lithium has 3 electrons: 1s² 2s¹, or [He] 2s¹ in noble-gas notation. Electrons per shell: 2, 1.

### How many valence electrons does lithium have?

Lithium has 1 valence electron (group 1).

### Is lithium a metal?

Yes. Lithium is a alkali metal.

### Where is lithium on the periodic table?

Lithium is in group 1 (alkali metals), period 2, in the s-block.

Data: [Periodic-Table-JSON](https://github.com/Bowserinator/Periodic-Table-JSON) (CC BY-SA 3.0); standard atomic weights from IUPAC (abridged). Values in brackets are the mass number of the longest-lived isotope.