Indium (In)
Indium (In) is element 49, a post-transition metal. Atomic mass 114.818, configuration [Kr] 4d¹⁰ 5s² 5p¹. Properties, isotopes, oxidation states, uses and history, with an interactive 3D atom model.
Key facts
| Atomic number | 49 |
|---|---|
| Symbol | In |
| Standard atomic weight | 114.818(1) |
| Category | Post-transition Metal |
| Group | 13 |
| Period | 5 |
| State at room temperature | Solid |
| Electron configuration | [Kr] 4d¹⁰ 5s² 5p¹ |
| Valence electrons | 3 |
| Common oxidation states | +3 |
| Common ions | No common ions |
| Electronegativity (Pauling) | 1.78 |
| First ionization energy | 558 kJ/mol |
| Electron affinity | 28.9 kJ/mol |
| Atomic radius | 156 pm |
| Density | 7.31 g/cm³ |
| Melting point | 156.60°C |
| Boiling point | 2072°C |
| Specific heat | 0.233 J/(g·°C) |
Natural isotopes
- In-113: Stable
- In-115: Radioactive
Common uses
- LCD/OLED screens (ITO)
- Solders
- Semiconductors
Where it matters
- Touchscreen Technology (Indium Tin Oxide films)
Hazards
- Compounds are toxic
- damage lungs/kidneys
History
| Discovered | 1863 |
|---|---|
| Discovered by | Ferdinand Reich & H.T. Richter |
| Name | From Indigo spectrum line |