Indium
A soft metal used in touchscreen indium-tin-oxide coatings.
Inside the Indium atom
Switch between Bohr and Quantum Cloud modes to compare a simple teaching model with a more realistic probability-based view, and follow the guided tour to explore the Indium atom step by step.
Electron configuration
[Kr] 4d10 5s2 5p1
A neutral Indium atom has 49 electrons (equal to its proton count). Choosing a different isotope above changes only the neutron count.
Shell distribution
Electrons fill inner shells before outer ones; the outermost (valence) shell drives the element's chemistry.
Physical & atomic properties
- State (room temp)
- Solid
- Melting point
- 430 K (157 °C)
- Boiling point
- 2345 K (2072 °C)
- Density
- 7.31 g/cm³
- Electronegativity
- 1.78 Pauling
- Atomic radius
- 155 pm
- 1st ionization energy
- 558 kJ/mol
- Category
- Post-transition metals
Discovery & naming
- Discovered
- 1863
- Discovered by
- Ferdinand Reich and Theodor Richter
- Origin of name
- The indigo line in its emission spectrum.
Notable uses
Touchscreen coatings, solders, and semiconductors.
Where Indium comes from
Several comparable sources
Both slow neutron capture in dying stars and rapid capture in explosive events contribute meaningfully.
Simplified origin map — many elements form through more than one astrophysical pathway.
Summary
- Atomic number
- 49
- Atomic mass
- 114.82
- Category
- Post-transition metals
- Group · Period
- 13 · 5
- Block
- p-block
- Shells
- 2 · 8 · 18 · 18 · 3