- A soft, silvery-white ductile metal which becomes a liquid above 28 °C, and whose atomic number is 55. It is extremely reactive, and has about 35 known isotopes, of which one is stable. It is strongly photoelectric, and is the most electropositive chemical element after francium. Some of its applications in electronics include its use in photocells, as a getter in vacuum tubes, and in cesium clocks. Its chemical symbol is Cs.
- chemical symbolCs