Atomic number 49
Indium
Post-transition metal
In the real world
Quick facts
- Atomic mass
- 114.82
- Group
- 13
- Period
- 5
- State (STP)
- solid
- Electronegativity
- 1.78
- Common ox. states
- +3
Properties
Electron configuration
[Kr] 4d¹⁰ 5s² 5p¹
- Ionization energy
- 558.3 kJ/mol
- Electron affinity
- 28.9 kJ/mol
- Melting point
- 429.75 K (156.6 °C)
- Boiling point
- 2345.00 K (2071.8 °C)
How dangerous is it?
1/5 · Low risk
A soft, silvery metal so gentle you can safely handle it; it even leaves a faint mark when scratched. Its dust and compounds are a lung concern only with long exposure.
- ToxicBuilds up over time
Breathing indium dust or its compounds over a long time can irritate and scar the lungs. (the bulk metal is low hazard; the concern is fine dust and compounds)
In factories the dust is controlled with ventilation and masks; the solid metal is safe to touch.
How it bonds
Indium normally shows +3 (In₂O₃, InCl₃) - predictable group-13 behavior, parallel to gallium. Indium tin oxide (ITO) is the transparent conductor in essentially every touchscreen and flat-panel display.
