Ryder has Why has the boulder changed A The heat of the Sun evaporated out the water, causing the boulder to shrink

B Wind and water have weathered the boulder, wearing away at its surface

C The weight of the boulder has caused its rock particles to compress

D The rock particles in the boulder have cemented into thinner layers​

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.

the answer is symmetrical : )