---
title: "Samarium (Sm) — element 62"
description: "Samarium is element 62, symbol Sm, atomic weight 150.36. Configuration, properties, uses and neighbours."
url: https://atoneplace.net/element/samarium/
site: "At One Place"
---

# Samarium (Sm)

**Samarium — element 62: Sm**

150.36 u · Lanthanide · period 6

Samarium-cobalt magnets are weaker than neodymium ones but keep working past 300 °C and barely corrode, which is why they are used in jet engine actuators and in electric motors that run hot. Samarium-149 is one of the strongest neutron absorbers known and is a significant reactor poison — it builds up in fuel and eats into the chain reaction. The element was named after samarskite, the mineral it came from, which was itself named after a Russian mining official, making samarium arguably the first element named after a living person.

## Properties

- **Atomic number:** 62
- **Symbol:** Sm
- **Standard atomic weight:** 150.36 u
- **Category:** Lanthanide
- **Period:** 6
- **Block:** f-block
- **Electron configuration:** [Xe] 6s² 4f⁶
- **Electrons per shell:** 2, 8, 18, 24, 8, 2
- **Melting point:** 1,347 K — 1073.8 °C — 1964.9 °F
- **Boiling point:** 2,067 K — 1793.8 °C — 3260.9 °F
- **Density:** 7.52 g/cm³
- **Electronegativity:** 1.17 (Pauling)
- **Oxidation states:** +3, +2
- **Discovered:** 1879 by Paul-Émile Lecoq de Boisbaudran

## Electron configuration

- **Full:** 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f⁶
- **Noble gas shorthand:** [Xe] 6s² 4f⁶
- **Shells:** K: 2 · L: 8 · M: 18 · N: 24 · O: 8 · P: 2

## What it is used for

- Samarium-cobalt magnets for high-temperature motors and aerospace
- Neutron-absorbing control rods in reactors
- Samarium-153 for pain relief in bone cancer
- Catalysts for dehydrating and dehydrogenating alcohols
- Headphone drivers and pickup magnets that must not lose strength when hot

## Neighbours in the table

| Z | Element | Symbol | Mass |
| --- | --- | --- | --- |
| 60 | Neodymium | Nd | 144.24 |
| 61 | Promethium | Pm | [145] |
| 62 | Samarium ← | Sm | 150.36 |
| 63 | Europium | Eu | 151.96 |
| 64 | Gadolinium | Gd | 157.25 |

## Common questions

### What is the atomic number of samarium?

62. That is the number of protons in its nucleus, which is what defines the element.

### What is the symbol for samarium?

Sm.

### What is the electron configuration of samarium?

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f⁶, or [Xe] 6s² 4f⁶ in noble-gas shorthand.

### What is the melting point of samarium?

1,347 K — 1073.8 °C — 1964.9 °F

## Related pages

- [Neodymium (Nd)](https://atoneplace.net/element/neodymium/)
- [Promethium (Pm)](https://atoneplace.net/element/promethium/)
- [Europium (Eu)](https://atoneplace.net/element/europium/)
- [Gadolinium (Gd)](https://atoneplace.net/element/gadolinium/)

## Sources

- Official vendor product documentation — At One Place (/about/)