---
title: "Rhodium (Rh): Atomic Mass, Electron Configuration & Properties"
url: https://www.moldraw.com/elements/rhodium.html
description: "Rhodium (Rh), element 45: atomic mass 102.91, electron configuration [Kr] 4d⁸ 5s¹, group 9, period 5, d-block transition metal. Melting and boiling point, density, electronegativity and shells."
lang: en
publisher: Scidart Academy
generated: 2026-11-04
---
45Rh102.91

# Rhodium (Rh) – element 45

Rhodium is a chemical element with the symbol **Rh** and atomic number **45**. It is a transition metal in group 9, period 5 of the periodic table (d-block), and is a solid at room temperature.

Rhodium (Rh) has atomic number 45, atomic mass 102.91 u and electron configuration [Kr] 4d8 5s1.

[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)

## Rhodium facts

| Symbol | Rh |
| --- | --- |
| Atomic number | 45 |
| Atomic mass | 102.91 u (g/mol) |
| Category | transition metal |
| Group | group 9 |
| Period | 5 |
| Block | d-block |
| Phase at 20 °C | Solid |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s1 4d8 |
| Noble-gas notation | [Kr] 4d8 5s1 |
| Electrons per shell | 2, 8, 18, 16, 1 |

## Bohr model and shells

Rhodium has 45 electrons in 5 shells: 2, 8, 18, 16, 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 | 2237 K (1963.8 °C) |
| --- | --- |
| Boiling point | 3968 K (3694.8 °C) |
| Density | 12.41 g/cm³ |
| Electronegativity (Pauling) | 2.28 |
| Electron affinity | 110.27 kJ/mol |
| Ionization energies | 719.7, 1740, 2997 kJ/mol (1st, 2nd, 3rd) |
| Molar heat capacity | 24.98 J/(mol·K) |
| Discovered by | William Hyde Wollaston |

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 Rh.

## Position in the periodic table

Tap any element to open its page.

## Frequently asked questions

### What is the atomic mass of rhodium?

The atomic mass of rhodium is 102.91 u, so one mole of rhodium atoms weighs 102.91 g.

### What is the electron configuration of rhodium?

Rhodium has 45 electrons: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s¹ 4d⁸, or [Kr] 4d⁸ 5s¹ in noble-gas notation. Electrons per shell: 2, 8, 18, 16, 1.

### Is rhodium a metal?

Yes. Rhodium is a transition metal.

### Where is rhodium on the periodic table?

Rhodium is in group 9, period 5, in the d-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.