Answer:
2 and 3
Step-by-step explanation:
A chemical reaction is defined as the process in which two or more reactants combined together chemically and gives a different product.
A balanced chemical equation involves an equal number of atoms on the reactant and product side. A balanced chemical reaction occurs when the atoms present on the reactant side or left side of the arrow is equal to the atoms on the product side or right side of the arrow.
The process of the balanced chemical equation is based on errors and trials in which the atoms in each element is identified, the atoms are then multiplied with required numbers, the addition of coefficient in front of molecules and check the equation at last.
Hence, the correct options are "2 and 3".