Atomic Element Z = 8 • Reactive Nonmetal

Oxygen (O) — Atomic Data, Electron Shells & Reactions

Oxygen (symbol O, atomic number 8) has a standard atomic weight of 15.999 u and ground-state configuration [He] 2s2 2p4.

← 7 N Full Atlas 9 F →

IUPAC Physical & Atomic Properties

Atomic Number (Z) 8 IUPAC Symbol O Standard Atomic Weight 15.999 g/mol Period / Group / Block 2 / 16 / p-block Condensed Electron Config [He] 2s2 2p4 Full Subshell Config 1s2 2s2 2p4 Principal Shell Occupancy [2, 6] Pauling Electronegativity 3.44 First Ionization Energy 1314 kJ/mol Covalent Radius 66 pm Melting Point 54.36 K (-218.79 °C) Boiling Point 90.2 K (-182.95 °C) Density 0.001429 g/cm³ Oxidation States -2, -1

Bohr Shell Diagram & Balanced Reactions

O (Z=8) — Valence shell highlighted in vermilion

Interactive Stoichiometry Reactions Involving Oxygen:

KMnO4 + HCl -> KCl + MnCl2 + Cl2 + H2O Cu + HNO3 -> Cu(NO3)2 + NO + H2O Cr2O7^2- + Fe^2+ + H+ -> Cr^3+ + Fe^3+ + H2O CO2 + H2O -> C6H12O6 + O2 C6H12O6 + O2 -> CO2 + H2O Fe2O3 + Al -> Fe + Al2O3