49 In 114.818

Indium

post-transition metal

Properties

Atomic number
49
Atomic mass
114.818 u
Category
post-transition metal
Group
13
Period
5
Block
p-block
State (room temp)
Solid
Outer-shell electrons
3
Electronegativity
1.78 (Pauling)
Density
7.31 g/cm³
Melting point
156.6 °C
Boiling point
2071.85 °C

Electron configuration

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p¹

Noble-gas shorthand: [Kr] 4d¹⁰ 5s² 5p¹

Electrons per shell: 2, 8, 18, 18, 3 — that's 3 in the outermost shell.

See how electron configuration is built →

In
Bohr model — outer-shell electrons in blue

About 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.

Position in the periodic table

Open the interactive periodic table →

Data compiled from Wikipedia, PubChem, and IUPAC. Source.