Answer:
1:2:1:2
Step-by-step explanation:
A molecule is made up of aggregates of small particles called atoms.
CH₄ + 2O₂ → CO₂ + 2H₂O
From the reaction above we have: 1 molecule of methane CH₄ reacting with 2 molecules of oxygen gas O₂ to produce 1 molecule of carbon dioxide gas CO₂ and 2 molecules of H₂O:
CH₄ + 2O₂ → CO₂ + 2H₂O
1 : 2 : 1 : 2