Please help with #3
I’ll mark if u gave a good answer

Ithink its solid. hope this

Combustion is the act or process of burning. therefore, i believe the answer is  a: burning wood. 

Answerchemical energy;

Answer is: hydrogen is being oxidized.chemical reaction: co₂ + h₂ → co + h₂o.oxidation half reaction: h₂ → 2h⁺ + 2e⁻.reduction half reaction: c⁺⁴ + 2e⁻ → c⁺².oxidation is increase of oxidation number, hydrogen change oxidation number from neutral charge (in molecule of hydrogen) to oxidation number +1 (in water).