Zirconium (Zr) — Atomic Data, Electron Shells & Reactions

Atomic Number (Z) 40 IUPAC Symbol Zr Standard Atomic Weight 91.224 g/mol Period / Group / Block 5 / 4 / d-block Condensed Electron Config [Kr] 4d2 5s2 Full Subshell Config 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d2 5s2 Principal Shell Occupancy [2, 8, 18, 10, 2] Pauling Electronegativity 1.33 First Ionization Energy 640 kJ/mol Covalent Radius 175 pm Melting Point 2128 K (1854.85 °C) Boiling Point 4682 K (4408.85 °C) Density 6.506 g/cm³ Oxidation States +4