Question

What is always the same between the reactants and products in a chemical reaction?

Answer 1

Mass and charge....

Explanation:

All chemical reactions (i) conserve mass, and (ii) conserve charge. And all reaction chemistry, and stoichiometry depend on these principles. And thus if we start with `1*g`, `10*g`, `1000*g` of reactants, we will necessarily finish with `1*g`, `10*g`, `1000*g` of product.