Atomic Number
49
Indium is a chemical element with symbol In and atomic number 49. It is a post-transition metal that makes up 0.21 parts per million of the Earth's crust.
49
114.82 u
post transition
solid
7.31 g/cm³
2, 8, 18, 18, 3
Protons: 49 • Electrons: 49 • Neutrons: Varies by isotope
Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p¹
1863 • Ferdinand Reich, Hieronymous Theodor Richter