49InIndium114.8181[Kr] 4d¹⁰ 5s² 5p¹
post-transition metal
Indium
Indium is a chemical element with symbol In and atomic number 49. It is a post-transition metallic element that is rare in Earth's crust. The metal is very soft, malleable and easily fusible, with a melting point higher than sodium, but lower than lithium or tin.
A stylized shell model. Electrons are quantum objects, not particles following these literal paths. Sizes and motion are illustrative.
Electrons by shell
Electron configuration
4d10
5s2
5p1
36 is the [Kr] core total across four shells.
At a glance
- Atomic number
- 49
- Atomic mass
- 114.8181 u
- Phase
- Solid
- Density
- 7.31 g/cm³
- Melting point
- 429.7485 K
- Boiling point
- 2,345 K
- First ionization energy
- 558.3 kJ/mol
- Electronegativity
- 1.78
- Electron affinity
- 37.043 kJ/mol
- Molar heat capacity
- 26.74 J/(mol·K)
- Period
- 5
- Appearance
- silvery lustrous gray
Conditions and isotopes affect measured properties. Some properties of short-lived elements are predicted. Electronegativity uses the Pauling scale.
Keep exploring
Explore the stories, imagery, and reference data in more depth. Properties with no value in the reference are marked unavailable.