All practice pages/Interatomic theory/Elements
Element 49, a post-transition metal
A metal soft enough to scratch with a fingernail, and the transparent conductor on every touchscreen.
Period 5, group 13. The other post-transition metals are tinted, and every cell opens its own article.
A metal that gives up its valence electrons to form positive ions, though less readily than the metals to its left.
Rare and never mined for itself. It is recovered from zinc ores during refining, mostly in China and South Korea.
Ferdinand Reich and Hieronymus Theodor Richter found it in 1863 while examining zinc ore with a spectroscope. Reich was color-blind, so Richter was the one who saw the bright indigo line that gave the element its name.
Most becomes indium tin oxide, a transparent film that conducts electricity on touchscreens, flat-panel displays and some solar cells. Indium also goes into low-melting solders, semiconductors such as the indium gallium nitride in LEDs, and seals for very cold equipment.