Answer:
3
Explanation:
There are three different elements in given chemical equation. These elements are hydrogen, oxygen and carbon.
Chemical equation:
2CH₄ + 4O₂ → 2CO₂ + 4H₂O
This equation shows the burning of methane. When methane burns in the presence of oxygen it produced water and carbondioxide.
We can see that all the reactant and product are made up of only three elements carbon, hydrogen and oxygen.
There are two reactant and two products in given reaction.
This reaction also follow the law of conservation of mass.
We can see that there are two carbon eight hydrogen and eight oxygen atoms on both side of equation.
This law was given by French chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.
