Atomic Element Z = 19 • Alkali Metal

Potassium (K) — Atomic Data, Electron Shells & Reactions

Potassium (symbol K, atomic number 19) has a standard atomic weight of 39.098 u and ground-state configuration [Ar] 4s1.

← 18 Ar Full Atlas 20 Ca →

IUPAC Physical & Atomic Properties

Atomic Number (Z) 19 IUPAC Symbol K Standard Atomic Weight 39.098 g/mol Period / Group / Block 4 / 1 / s-block Condensed Electron Config [Ar] 4s1 Full Subshell Config 1s2 2s2 2p6 3s2 3p6 4s1 Principal Shell Occupancy [2, 8, 8, 1] Pauling Electronegativity 0.82 First Ionization Energy 419 kJ/mol Covalent Radius 203 pm Melting Point 336.7 K (63.55 °C) Boiling Point 1032 K (758.85 °C) Density 0.862 g/cm³ Oxidation States +1

Bohr Shell Diagram & Balanced Reactions

K (Z=19) — Valence shell highlighted in vermilion

Interactive Stoichiometry Reactions Involving Potassium:

KMnO4 + HCl -> KCl + MnCl2 + Cl2 + H2O K4[Fe(CN)6] + H2SO4 + H2O -> K2SO4 + FeSO4 + (NH4)2SO4 + CO Pb(NO3)2 + KI -> PbI2 + KNO3 KClO3 -> KCl + O2 KMnO4 + H2C2O4 + H2SO4 -> K2SO4 + MnSO4 + CO2 + H2O