Final answer:
Chemical reactions transform substances through the breaking and forming of bonds between atoms, involving reactants that start the reaction and products that are formed. The law of conservation of mass ensures the same number of atoms are present in both reactants and products. Option 3 is correct.
Step-by-step explanation:
Components of a Chemical Reaction
Chemical reactions involve the transformation of substances through the breaking and forming of bonds between atoms. The starting materials of a chemical reaction are known as reactants, usually found on the left side of a chemical equation.
The substances that are produced by the chemical reaction are referred to as the products, which are typically found on the right side of the equation. An arrow is used to represent the direction of the reaction, starting from the reactants and pointing towards the products.
The reactants and products can be elements or compounds, and a molecule is a combination of two or more atoms bonded together. In every chemical equation, the number and types of atoms must remain constant from reactants to products to adhere to the law of conservation of mass. For example, the formation of water from hydrogen and oxygen is represented by the chemical equation 2H2 + O2 → 2H2O.