Which property indicates how light is reflected from a mineral surface

You use the atomic number to find out how many protons and neutrons there are in the atom. you use the atomic mass to find out how many protons and electrons there are in the atom. 

What record? the question is incomplete

In reversible reaction chemistry equilibrium is attained when the forward and reverse reactions are taking place at the same rate, thus, the concentrations of reactants and products remain the same. a reversible reaction is a chemical reaction where the reactants form products that, in turn, react together to give the reactants back. in irreversible reactions on the other hand, the reactants react to form the products, which cannot revert back into reactants.