The weakest type of force between particles of a substance is termed

The answer is vanderwaals forces. They are the weak forces of attraction or repulsion between molecules that are close together. This is due to the fact that the electron cloud of an atom keeps shifting and never stays in one position. Therefore, there is always a momentary and differential formation of dipoles in an atom as a result.

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.