Francium (Fr) — Atomic Data, Electron Shells & Reactions

Atomic Number (Z) 87 IUPAC Symbol Fr Standard Atomic Weight 223 g/mol Period / Group / Block 7 / 1 / s-block Condensed Electron Config [Rn] 7s1 Full Subshell Config 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p6 7s1 Principal Shell Occupancy [2, 8, 18, 32, 18, 8, 1] Pauling Electronegativity 0.7 First Ionization Energy 380 kJ/mol Covalent Radius 260 pm Melting Point 300 K (26.85 °C) Boiling Point 950 K (676.85 °C) Density 1.87 g/cm³ Oxidation States +1