Subject classification: this is a chemistry resource.
Completion status: this resource is just getting off the ground. Please feel welcome to help!
Type classification: this is an article resource.
Educational level: this is a research resource.
Cesium (US), or caesium, is a chemical element.
Discovery
Kirchhoff and Bunsen
Two German scientists (Gustav Kirchhoff and Robert Bunsen), in 1860, discovered Cesium in samples of mineral water in Bad Dürkheim, a spa town in Germany. Because of two blue lines from its emission spectrum, they chose the name, caesius, which is Latin for "sky blue".