An atom can be called a particle, but a molecule is never called a particle

it's because a particle is a very small matter piece, and an atom is a very small piece of matter, but a particle is some atoms joined together to make a substance, but a particle, which is made from atoms, can't be called atoms.

Explanation:

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.

it’s previous models   because when i picked that son of a gun’s answer it was wrong look for previous models because they might make it a different letter