What are the properties of the reactants?

Reactants starts the chemical reaction and gives right to the product either by thermal decomposition or in the presence of a catalyst.

Explanation:

Reactants and products contain the same atoms, but they are rearranged during the reaction, so reactants and products are different substances.

The properties of reactant are:

1. it contains the same atoms

2. it describes the pathway of the reaction.

am i too late?

explanation:

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.