In
Indium
Element 49 · 114.82 u
Indium is a soft, malleable post-transition metal used in touchscreen displays.
Physical Properties
| Atomic Mass | 114.82 u |
| Density | 7.31 g/cm³ |
| Melting Point | 429.75 K |
| Boiling Point | 2345.0 K |
| Appearance | Silvery-white lustrous metallic |
| State at Room Temp | Solid |
Chemical Properties
| Electronegativity | 1.78 (Pauling) |
| 1st Ionization Energy | 558.3 kJ/mol |
| Electron Affinity | 28.9 kJ/mol |
| Oxidation States | +1, +2, +3 |
Atomic Properties
| Electron Configuration | [Kr] 4d10 5s2 5p1 |
| Atomic Radius | 167.0 pm |
| Covalent Radius | 142.0 pm |
| Van der Waals Radius | 193.0 pm |
Discovery
| Discovered By | Ferdinand Reich, Hieronymous Theodor Richter |
| Discovery Year | 1863 |
| Location | Freiberg, Germany |
| Named After | Latin 'indicum' meaning indigo, from its spectral line |
About Indium
Indium is very soft, silvery-white, and brilliant. It can be cut with a knife and leaves a streak on paper. It was discovered by its bright indigo spectral line.
Uses & Applications
Touchscreen displays (indium tin oxide), solders, semiconductors, and low-melting-point alloys.
Fun Fact
When you bend indium, it makes a characteristic 'tin cry' -- a high-pitched crackling sound as the crystal structure deforms.
Isotopes
| Mass Number | Abundance | Half-Life | Stable |
| 113 | 0.0429% | - | Yes |
| 115 | 0.9571% | 4.41e14 years | No |
Electron Configuration
[Kr] 4d10 5s2 5p1