Elements / 55
55Cs132.91
Cesium
Alkali metal · s-block · ring P · spoke 1
Cesium is element 55, an alkali metal. It sits on ring P (period 6) on spoke 1, the alkali metals. Follow that spoke toward the center and out again to find its chemical relatives.
Properties
| Density | 1.93 g/cm³ | Terrain → |
|---|---|---|
| Melting point | 302 K · 29 °C | Terrain → |
| Boiling point | 944 K · 671 °C | Terrain → |
| Electronegativity | 0.79 | Terrain → |
| First ionization energy | 376 kJ/mol | Terrain → |
| Atomic weight | 132.905 u | Terrain → |
| Crustal abundance | 3 ppm | Terrain → |
| Discovered | 1860 | Terrain → |
Values from open reference data; see sources. "Terrain" opens that property as a 3D landscape across the whole spiral.
Two things you might not know
- The first element discovered with a spectroscope, found in 1860 by Bunsen and Kirchhoff in mineral water from Dürkheim, Germany.
- The SI second is 9,192,631,770 cycles of its clock transition; it melts at 28.5 °C, so it is liquid near room temperature.
Checked against en.wikipedia.org.
Spoke 1: Alkali metals
Ring P (period 6)
Play with Cesium
Watch it fly into its seat, or raise the whole spiral into a landscape and see where it peaks.