Indium (symbol In, atomic number 49) is a soft metal used in the transparent conductor of touchscreens and solar cells. It is classified as a post-transition metal and sits in group 13, period 5 of the periodic table.
Overview
Indium is the chemical element with atomic number 49 and the symbol In. With a standard atomic weight of 114.82, it is a post-transition metal. In the periodic table it occupies group 13 and period 5, and under standard conditions it is normally a solid. Indium is a soft metal used in the transparent conductor of touchscreens and solar cells.
Atomic structure
An atom of Indium has 49 protons in its nucleus and, when neutral, 49 electrons arranged in the configuration [Kr] 4d10 5s2 5p1. Its standard atomic weight of 114.82 reflects the natural mix of its stable isotopes.
Discovery and place in the table
Indium was discovered in 1863 by Ferdinand Reich, Hieronymous Theodor Richter. It follows Cadmium (Cd) and precedes Tin (Sn) in order of atomic number.
| Atomic number | 49 |
|---|---|
| Symbol | In |
| Atomic mass | 114.82 |
| Category | Post-transition metal |
| Group | 13 |
| Period | 5 |
| Electron configuration | [Kr] 4d10 5s2 5p1 |
| Phase at STP | Solid |
| Discovered | 1863 (Ferdinand Reich, Hieronymous Theodor Richter) |