The chemical symbol for Potassium is K and its atomic number is 19.
We find it listed in the periodic table of elements in group 1 and period 4, and block s.
Potassium belongs to the family of alkali metals such as for example cesium
This element is stable.
Potassium came from Pottash a german name, notice that Potassium has a latin origin too.
Atomic number (Z) 19
Group, block group 1 (alkali metals), s-block
Period: 4
Element category: alkali metal
Standard atomic weight (±) (Ar): 39.0983(1)[1]
Electron configuration: [Ar] 4s1
per shell 2, 8, 8, 1
Phase: solid
Melting point: 336.7 K (63.5 °C, 146.3 °F)
Boiling point: 1032 K (759 °C, 1398 °F)
Density near r.t.: 0.862 g/cm3
when liquid, at m.p. 0.828 g/cm3
Critical point: 2223 K, 16 MPa[2]
Heat of fusion: 2.33 kJ/mol
Heat of vaporization: 76.9 kJ/mol
Molar heat capacity : 29.6 J/(mol•K)
Atomic properties
Oxidation states: +1, −1 (a strongly basic oxide)
Electronegativity: Pauling scale: 0.82
Ionization energies: 1st: 418.8 kJ/mol
2nd: 3052 kJ/mol
3rd: 4420 kJ/mol
Atomic radius empirical: 227 pm
Covalent radius: 203±12 pm
Van der Waals radius: 275 pm
Crystal structure: body-centered cubic (bcc)
Speed of sound thin rod 2000 m/s (at 20 °C)
Thermal expansion 83.3 µm/(m•K) (at 25 °C)
Thermal conductivity: 102.5 W/(m•K)
Electrical resistivity: 72 nΩ•m (at 20 °C)
Magnetic ordering paramagnetic[3]
Young's modulus: 3.53 GPa
Shear modulus :1.3 GPa
Bulk modulus: 3.1 GPa
Mohs hardness: 0.4
Brinell hardness: 0.363 MPa
CAS Number 7440-09-7
