---
title: "Germanium (Ge) — element 32"
description: "Germanium is element 32, symbol Ge, atomic weight 72.63. Configuration, properties, uses and neighbours."
url: https://atoneplace.net/element/germanium/
site: "At One Place"
---

# Germanium (Ge)

**Germanium — element 32: Ge**

72.63 u · Metalloid · period 4, group 14

The first transistor, built at Bell Labs in 1947, was germanium, not silicon — germanium was easier to purify at the time, and it took another decade for silicon to win on heat tolerance and on the quality of its oxide. It is transparent to infrared and opaque to visible light, so a germanium window looks like polished metal but a thermal camera sees straight through it. Mendeleev predicted it as eka-silicon in 1871 and Winkler's 1886 measurements matched the prediction closely enough to settle most remaining doubts about the periodic table.

## Properties

- **Atomic number:** 32
- **Symbol:** Ge
- **Standard atomic weight:** 72.63 u
- **Category:** Metalloid
- **Group:** 14
- **Period:** 4
- **Block:** p-block
- **Electron configuration:** [Ar] 4s² 3d¹⁰ 4p²
- **Electrons per shell:** 2, 8, 18, 4
- **Melting point:** 1,211.4 K — 938.3 °C — 1720.9 °F
- **Boiling point:** 3,106 K — 2832.8 °C — 5131.1 °F
- **Density:** 5.323 g/cm³
- **Electronegativity:** 2.01 (Pauling)
- **Oxidation states:** +4, +2
- **Discovered:** 1886 by Clemens Winkler

## Electron configuration

- **Full:** 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p²
- **Noble gas shorthand:** [Ar] 4s² 3d¹⁰ 4p²
- **Shells:** K: 2 · L: 8 · M: 18 · N: 4

## What it is used for

- Infrared lenses for thermal imaging and night vision
- Fibre-optic cable cores, where it raises the refractive index
- The catalyst for making PET plastic bottles
- Silicon-germanium chips in phone radios and high-speed circuits
- Space solar cells, as the substrate for multi-junction stacks

## Neighbours in the table

| Z | Element | Symbol | Mass |
| --- | --- | --- | --- |
| 30 | Zinc | Zn | 65.38 |
| 31 | Gallium | Ga | 69.723 |
| 32 | Germanium ← | Ge | 72.63 |
| 33 | Arsenic | As | 74.922 |
| 34 | Selenium | Se | 78.971 |

## Group 14

Elements in the same group share their outer electron count, which is why they behave similarly in reactions. Germanium sits in group 14 with carbon, silicon, tin, lead, flerovium.

## Common questions

### What is the atomic number of germanium?

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

### What is the symbol for germanium?

Ge.

### What is the electron configuration of germanium?

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p², or [Ar] 4s² 3d¹⁰ 4p² in noble-gas shorthand.

### What is the melting point of germanium?

1,211.4 K — 938.3 °C — 1720.9 °F

## Related pages

- [Zinc (Zn)](https://atoneplace.net/element/zinc/)
- [Gallium (Ga)](https://atoneplace.net/element/gallium/)
- [Arsenic (As)](https://atoneplace.net/element/arsenic/)
- [Selenium (Se)](https://atoneplace.net/element/selenium/)
- [Carbon (C)](https://atoneplace.net/element/carbon/)
- [Silicon (Si)](https://atoneplace.net/element/silicon/)
- [Tin (Sn)](https://atoneplace.net/element/tin/)
- [Lead (Pb)](https://atoneplace.net/element/lead/)
- [Flerovium (Fl)](https://atoneplace.net/element/flerovium/)

## Sources

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