19th Century
24 elements
Helium
Discovered in the Sun before it was found on Earth, via solar spectrum analysis....
Fluorine
The most reactive and electronegative element. Reacts with almost every other el...
Neon
The fifth most abundant element in the universe but rare on Earth. Neon signs pr...
Argon
The third most abundant gas in Earths atmosphere at 0.93%. Used in welding to pr...
Scandium
Named after Scandinavia where it was discovered. Used in aerospace alloys with a...
Gallium
Melts at just 29.8C, it will melt in your hand. Used in semiconductors as galliu...
Germanium
A semiconductor used in early transistors before silicon became dominant. Still ...
Krypton
Not from Supermans home planet, the element came first. Used in high-performance...
Rubidium
Discovered by its dark red spectral lines, the name means dark red. Extremely re...
Indium
Named for its indigo blue spectral line. Indium tin oxide is the transparent con...
Xenon
The name means stranger in Greek, as it was unexpected. Used in high-intensity l...
Cesium
The international definition of a second is based on the cesium-133 atom. Most r...
Praseodymium
Used in magnets for hybrid car motors and wind turbine generators. Praseodymium ...
Neodymium
Neodymium magnets are the strongest permanent magnets ever made. Essential for w...
Gadolinium
Used as MRI contrast agent to highlight blood vessels and tumors. Has the highes...
Samarium
Named after Vasily Samarsky-Bykhovets, the first element named for a person. Sam...
Dysprosium
From the Greek dysprositos, meaning hard to get at, because it took decades to i...
Holmium
Has the highest magnetic strength of any element, so it concentrates magnetic fi...
Thulium
The rarest of the stable rare earths, named after Thule, the mythical farthest n...
Ytterbium
The fourth and final element named after the Swedish village of Ytterby. Ytterbi...
Thallium
Discovered by its bright green spectral line, from the Greek thallos, a green sh...
Polonium
Marie Curies first discovery, named after her homeland Poland, and the first ele...
Radium
The celebrated discovery of Marie and Pierre Curie, from tons of uranium ore, na...
Actinium
Glows an eerie pale blue in the dark as its radiation excites the surrounding ai...