( ( The ( ( reactants and ) products ) ) ( ( must ( contain ( ( the ( same number ) ) ( of ( atoms ( making ( ( the reaction ) balanced ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NNS reactants) (CC and) (NNS products)) (VP (MD must) (VP (VB contain) (NP (NP (DT the) (JJ same) (NN number)) (PP (IN of) (NP (NP (NNS atoms)) (VP (VBG making) (NP (NP (DT the) (NN reaction)) (VP (VBN balanced))))))))) (. .)))
The reactants and products must contain the same number of atoms making the reaction balanced.
(ROOT (S (NP (NNS Atoms)) (VP (VBP make) (NP (NNS products)) (PP (IN by) (S (VP (VBG rearranging) (NP (PRP$ their) (NN chemical) (NNS bonds)) (PP (IN in) (NP (DT a) (NN reactant))))))) (. .)))