---
title: "Niobium (Nb): Atomic Mass, Electron Configuration & Properties"
url: https://www.moldraw.com/elements/niobium.html
description: "Niobium (Nb), element 41: atomic mass 92.906, electron configuration [Kr] 4d⁴ 5s¹, group 5, period 5, d-block transition metal. Melting and boiling point, density, electronegativity and shells."
lang: en
publisher: Scidart Academy
generated: 2026-11-03
---
41Nb92.906

# Niobium (Nb) – element 41

Niobium is a chemical element with the symbol **Nb** and atomic number **41**. It is a transition metal in group 5, period 5 of the periodic table (d-block), and is a solid at room temperature.

Niobium (Nb) has atomic number 41, atomic mass 92.906 u and electron configuration [Kr] 4d4 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)

## Niobium facts

| Symbol | Nb |
| --- | --- |
| Atomic number | 41 |
| Atomic mass | 92.906 u (g/mol) |
| Category | transition metal |
| Group | group 5 |
| Period | 5 |
| Block | d-block |
| Phase at 20 °C | Solid |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s1 4d4 |
| Noble-gas notation | [Kr] 4d4 5s1 |
| Electrons per shell | 2, 8, 18, 12, 1 |

## Bohr model and shells

Niobium has 41 electrons in 5 shells: 2, 8, 18, 12, 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 | 2750 K (2476.8 °C) |
| --- | --- |
| Boiling point | 5017 K (4743.9 °C) |
| Density | 8.57 g/cm³ |
| Electronegativity (Pauling) | 1.6 |
| Electron affinity | 88.516 kJ/mol |
| Ionization energies | 652.1, 1380, 2416 kJ/mol (1st, 2nd, 3rd) |
| Molar heat capacity | 24.6 J/(mol·K) |
| Discovered by | Charles Hatchett |

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 Nb.

## Position in the periodic table

Tap any element to open its page.

## Frequently asked questions

### What is the atomic mass of niobium?

The atomic mass of niobium is 92.906 u, so one mole of niobium atoms weighs 92.906 g.

### What is the electron configuration of niobium?

Niobium has 41 electrons: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s¹ 4d⁴, or [Kr] 4d⁴ 5s¹ in noble-gas notation. Electrons per shell: 2, 8, 18, 12, 1.

### Is niobium a metal?

Yes. Niobium is a transition metal.

### Where is niobium on the periodic table?

Niobium is in group 5, 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.