By Randal Nelson
https://www.cs.rochester.edu/~nelson/cesium/cesium_faq.html
- 9193 MHz hyperfine transition
- 99.9% pure Cesium metal has a street value of $161.10 per gram
- used as a getter in vacuum systems due to its high affinity for oxygen
- clocks are accurate to better than one second in a million years
- The richest known deposit occurs at Bernic Lake Manitoba
- Atomic number 55, Cesium is the heaviest of the natural alkali metals
- It melts at 28.4 C (84 F), just below body heat, and boils at 669.3 C