Comparison of Potassium and Cesium

Attribute	Potassium ×	Cesium ×
Atomic mass (u)	39.0983	132.905452
Standard state	Solid	Solid
Oxidation states	+1	+1
Electron configuration	[Ar]4s¹	[Xe]6s¹
Atomic radius (van der waals) (pm)	275	343
Electronegativity (pauling scale)	0.82	0.79
Electron affinity (eV)	0.501	0.472
Ionization energy (eV)	4.341	3.894
Boiling point (K)	1032	944
Melting point (K)	336.53	301.59
Density (g/cm³)	0.89	1.93
Atomic number	19	55
Group name	Alkali metal	Alkali metal
Discovered (year)	1807	1860
Symbol	K	Cs