Answer:
b) O₂
d) CH₄
Step-by-step explanation:
In a chemical equation, the reactants are the substances that are written on the left side. The reactants react to produce the products. On the right side, the products are written.
The arrow => is used to separate the reactants from the products.
To the left of the arrow, you can see this written:
CH₄ + 2O₂
The plus sign + is used to separate each reactant.
In 2O₂ you can ignore the big 2 because it is a coefficient, which is written to balance the equation.
The reactants are CH₄ and O₂