Cesium is a soft, silvery-gold alkali metal, noted for its extreme reactivity. It is the most electropositive naturally occurring element, giving it unique properties, and its stable isotopes define the second in atomic clocks.
Cesium is a soft, silvery-gold alkali metal, noted for its extreme reactivity. It is the most electropositive naturally occurring element, giving it unique properties, and its stable isotopes define the second in atomic clocks.