---
title: "Uranium (U): Atomic Mass, Electron Configuration & Properties"
url: https://www.moldraw.com/elements/uranium.html
description: "Uranium (U), element 92: atomic mass 238.03, electron configuration [Rn] 5f³ 6d¹ 7s², group 3, period 7, f-block actinide. Melting and boiling point, density, electronegativity and shells."
lang: en
publisher: Scidart Academy
generated: 2026-11-03
---
92U238.03

# Uranium (U) – element 92

Uranium is a chemical element with the symbol **U** and atomic number **92**. It is a actinide in group 3 (actinides), period 7 of the periodic table (f-block), and is a solid at room temperature.

Uranium (U) has atomic number 92, atomic mass 238.03 u and electron configuration [Rn] 5f3 6d1 7s2.

[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)

## Uranium facts

| Symbol | U |
| --- | --- |
| Atomic number | 92 |
| Atomic mass | 238.03 u (g/mol) |
| Category | actinide |
| Group | group 3 (actinides) |
| Period | 7 |
| Block | f-block |
| Phase at 20 °C | Solid |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f3 6d1 |
| Noble-gas notation | [Rn] 5f3 6d1 7s2 |
| Electrons per shell | 2, 8, 18, 32, 21, 9, 2 |

## Bohr model and shells

Uranium has 92 electrons in 7 shells: 2, 8, 18, 32, 21, 9, 2. 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 | 1405.3 K (1132.2 °C) |
| --- | --- |
| Boiling point | 4404 K (4130.9 °C) |
| Density | 19.1 g/cm³ |
| Electronegativity (Pauling) | 1.38 |
| Electron affinity | 50.94 kJ/mol |
| Ionization energies | 597.6, 1420 kJ/mol (1st, 2nd) |
| Molar heat capacity | 27.665 J/(mol·K) |
| Discovered by | Martin Heinrich Klaproth |

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 U.

## Position in the periodic table

Tap any element to open its page.

## Frequently asked questions

### What is the atomic mass of uranium?

The atomic mass of uranium is 238.03 u, so one mole of uranium atoms weighs 238.03 g.

### What is the electron configuration of uranium?

Uranium has 92 electrons: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 5f³ 6d¹, or [Rn] 5f³ 6d¹ 7s² in noble-gas notation. Electrons per shell: 2, 8, 18, 32, 21, 9, 2.

### Is uranium a metal?

Yes. Uranium is a actinide.

### Where is uranium on the periodic table?

Uranium is in group 3 (actinides), period 7, in the f-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.