Periodic TableAll elementsIndium
No. 049
In
114.82 u
Element · Post-Transition Metal

Indium

Indium (铟, symbol In) is chemical element number 49, a Post-Transition Metal in period 5, group 13 of the periodic table, with a standard atomic weight of about 114.82. Soft, silvery post-transition metal. Used in touchscreens (indium tin oxide) and solders.

Period 5Group 13[Kr] 4d¹⁰ 5s² 5p¹

Properties

Atomic number49
SymbolIn
Atomic mass114.82 u
CategoryPost-Transition Metal
Period5
Group13
Electron configuration[Kr] 4d¹⁰ 5s² 5p¹
Electronegativity1.78
Covalent radius142 pm
Density7.31 g/cm³
Melting point429.75 K
Boiling point2345 K
DiscoveryReich & Richter, 1863

Overview

Soft, silvery post-transition metal. Used in touchscreens (indium tin oxide) and solders. Element 49, Indium (In), is a Post-Transition Metal found in period 5, group 13. As a post-transition metal it is fairly soft with a low melting point, turning up in alloys, solders and coatings.

With 3 electrons in its outermost shell, Indium bonds accordingly; full configuration [Kr] 4d¹⁰ 5s² 5p¹, electronegativity 1.78. At room temperature it is normally a solid; it melts near 429.75 K (156.6 °C), boils near 2345 K (2071.9 °C), has a density around 7.31 g/cm³.

Common applications range across Electronics / Semiconductors. It was first described by Reich & Richter in 1863. The periodic trends guide explains the underlying patterns.

Electron shells

In49

Electrons per shell: 2 · 8 · 18 · 18 · 3

Main uses

Hazard

LowNo special hazard flags.

Compounds containing Indium

No compounds in this knowledge base contain Indium yet.

Data sources

Atomic mass uses IUPAC (CIAAW) standard atomic weights; the covalent radius is from Cordero et al. (2008). Verify on the RSC Periodic Table, PubChem and Wikipedia. Educational reference only.