Atomic Element Z = 17 • Halogen

Chlorine (Cl) — Atomic Data, Electron Shells & Reactions

Chlorine (symbol Cl, atomic number 17) has a standard atomic weight of 35.45 u and ground-state configuration [Ne] 3s2 3p5.

← 16 S Full Atlas 18 Ar →

IUPAC Physical & Atomic Properties

Atomic Number (Z) 17 IUPAC Symbol Cl Standard Atomic Weight 35.45 g/mol Period / Group / Block 3 / 17 / p-block Condensed Electron Config [Ne] 3s2 3p5 Full Subshell Config 1s2 2s2 2p6 3s2 3p5 Principal Shell Occupancy [2, 8, 7] Pauling Electronegativity 3.16 First Ionization Energy 1251 kJ/mol Covalent Radius 102 pm Melting Point 171.6 K (-101.55 °C) Boiling Point 239.11 K (-34.04 °C) Density 0.003214 g/cm³ Oxidation States +7, +5, +1, -1

Bohr Shell Diagram & Balanced Reactions

Cl (Z=17) — Valence shell highlighted in vermilion

Interactive Stoichiometry Reactions Involving Chlorine:

KMnO4 + HCl -> KCl + MnCl2 + Cl2 + H2O AgNO3 + CaCl2 -> AgCl + Ca(NO3)2 KClO3 -> KCl + O2 Al + HCl -> AlCl3 + H2