Which part of an atom would be found orbiting the nucleus?

electrons

Electrons are negatively charged particles that orbit the nucleus. The number of electrons depends on the element and it is an ion or not

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.