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Indium

Atomic number: 49Mass: 114.818 uCategory: Post-Transition Metal

About Indium

Indium is a post-transition metal that makes up 0.21 parts per million of the Earth's crust. It is a very soft, silvery-white metal. Indium tin oxide (ITO) is transparent and conductive, making it essential for touchscreens.

Properties

Period
5
Group
13
Block
P
Category
Post-Transition Metal
Electronegativity
1.78 (Pauling)
Ionization Energy
558.3 kJ/mol
Melting Point
430 K (157°C)
Boiling Point
2345 K (2072°C)
Density
7.31 g/cm³
Oxidation States
+3

Electron Configuration

1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p¹
[Kr] 4d¹⁰ 5s² 5p¹
Shell 1:2e⁻
Shell 2:8e⁻
Shell 3:18e⁻
Shell 4:18e⁻
Shell 5:3e⁻

Real-World Uses

Touchscreens (ITO)
LCD displays
Semiconductors
Low-melting alloys
Bearings

Fun Fact

Every touchscreen you've ever used likely contains indium — it's the element that makes touch displays possible!