Final answer:
The relationship between the substances in a chemical equation depends on the type of reaction: combination reaction, dynamic equilibrium, reversible reaction, or combustion reaction. A balanced chemical equation shows the conservation of mass, where the same number and types of atoms are found in both reactants and products.
Step-by-step explanation:
The relationship between the substances in a chemical equation can be described based on the type of reaction taking place. If two substances combine to form a new compound, as in the general form A+B → AB, this is known as a combination reaction or synthesis reaction. When substances exist in a dynamic equilibrium, they undergo reversible reactions where the reactants and products are present in a balance without any net change. A reversible chemical reaction is one in which the products can revert to the original reactants under certain conditions. Lastly, if the reactants are burning in the presence of oxygen to produce energy, as in methane's combustion (CH4 + 2O2 → CO2 + 2H2O), it is characterized as a combustion reaction.
Chemical reactions are depicted by equations, with reactants on the left, joined by a plus sign and an arrow pointing to the products on the right. The substances are represented by chemical formulas, and the equation shows how atoms rearrange during the reaction. It's crucial that a chemical equation is balanced, meaning it has the same number and type of atoms on both sides, adhering to the law of conservation of mass.