An electron in the highest occupied energy level of an atom would be

Valence electrons are the electrons in the highest occupied principal energy level of an atom.

so what is the problem with your lab report and whats the subject of the lab report? i will you

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.