reactant
NO substance is classified as reactant or product individually.Reactant is a substance which undergoes chemical reaction to give a new product,which is called product.Example:-Water + Sulphur Trioxide --------> Sulphuric acidHere water and sulphur trioxide are reactants and sulphuric acid is the product.Water can be both a reactant and product.
This depends on the reaction involved.
Reactant
sulfur is a reactant
Oxygen is a reactant
product
Reactant- glucose and product- carbon dioxide.
Sugar can be both a reactant and a product, depending on the chemical reaction. For example, in the process of photosynthesis, sugar (glucose) is produced as a product. However, in the process of fermentation, sugar is a reactant that is broken down to produce other products like ethanol and carbon dioxide.
Glucose is a product of photosynthesis and a reactant in cellular respiration.
For copper, it is an element. It could be both reactant and product. While purifying copper will be the product. But copper would be the reactant in case of preparing hydrogen or copper sulphate salts.
Any
Chlorine can be both a reactant and a product, depending on the chemical reaction it is involved in. It can react with other substances to form new compounds as a reactant, or it can be generated as a product from certain reactions.