Atomic Element Z = 26 • Transition Metal

Iron (Fe) — Atomic Data, Electron Shells & Reactions

Iron (symbol Fe, atomic number 26) has a standard atomic weight of 55.845 u and ground-state configuration [Ar] 3d6 4s2.

← 25 Mn Full Atlas 27 Co →

IUPAC Physical & Atomic Properties

Atomic Number (Z) 26 IUPAC Symbol Fe Standard Atomic Weight 55.845 g/mol Period / Group / Block 4 / 8 / d-block Condensed Electron Config [Ar] 3d6 4s2 Full Subshell Config 1s2 2s2 2p6 3s2 3p6 3d6 4s2 Principal Shell Occupancy [2, 8, 14, 2] Pauling Electronegativity 1.83 First Ionization Energy 762 kJ/mol Covalent Radius 132 pm Melting Point 1811 K (1537.85 °C) Boiling Point 3134 K (2860.85 °C) Density 7.874 g/cm³ Oxidation States +3, +2

Bohr Shell Diagram & Balanced Reactions

Fe (Z=26) — Valence shell highlighted in vermilion

Interactive Stoichiometry Reactions Involving Iron:

Cr2O7^2- + Fe^2+ + H+ -> Cr^3+ + Fe^3+ + H2O Fe2O3 + Al -> Fe + Al2O3 K4[Fe(CN)6] + H2SO4 + H2O -> K2SO4 + FeSO4 + (NH4)2SO4 + CO FeS2 + O2 -> Fe2O3 + SO2