Cs
Cesium · element 55
Alkali Metal · Solid at room temperature
Caesium or cesium is a chemical element with symbol Cs and atomic number 55. It is a soft, silvery-gold alkali metal with a melting point of 28 °C (82 °F), which makes it one of only five elemental metals that are liquid at or near room temperature. Caesium is an alkali metal and has physical and chemical properties similar to those of rubidium and potassium.
Key facts
Atomic mass
132.905451966 u
how heavy one atom is
Phase (room temp.)
Solid
Density
1.93 g/cm³
how tightly packed it is
Melting point
301.7 K (29 °C)
when solid turns to liquid
Boiling point
944 K (671 °C)
when liquid turns to gas
Period
6
its row in the periodic table
Group
1
its column in the periodic table
Block
S-block
the neighbourhood it lives in
Electronegativity
0.79
how strongly it pulls electrons
Electron configuration
[Xe] 6s1
where its electrons live
Shells
2 · 8 · 18 · 18 · 8 · 1
electrons in each layer, inside to out
Discovered by
Robert Bunsen
who found it
Appearance
silvery gold
what it looks like
Source: Wikipedia