Im so confused : ( balance the following redox equation. make sure to show the work needed to balance a redox reaction. zn + o2 → zn2+ + o2-

Answer is: 2Zn + O₂ → 2ZnO (2Zn²⁺ + 2O²⁻).
Unbalanced chemical reaction: Zn + O₂ → ZnO.
Zn → Zn²⁺ + 2e⁻ / ×2; 2Zn → 2Zn²⁺ + 4e⁻.
4e⁻ + O₂ → 2O²⁻.
Zinc lost two electrons and became Zn²⁺, molecule of oxygen gain four electrons and become 2O²⁻.  Multiply first reaction with two to have same number of electrons and put coefficients in chemical reaction.

Spontaneity tell us the direction of the reaction, but not how fast it goes. gibbs free energy brings together enthalpy, entropy and temperature in one easy formula. g = h - ts. and, finally the sign of delta g is always negative for a spontaneous reaction.