( Atoms ( ( are ( ( neutral so ) ( that ( means ( that ( ( ( ( the ( positive protons ) ) and ) ( the ( negative electrons ) ) ) ( must ( be ( equal ( for ( the ( atom ( to ( be neutral ) ) ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Atoms)) (VP (VBP are) (ADJP (JJ neutral) (RB so) (SBAR (WHNP (WDT that)) (S (VP (VBZ means) (SBAR (IN that) (S (NP (NP (DT the) (JJ positive) (NNS protons)) (CC and) (NP (DT the) (JJ negative) (NNS electrons))) (VP (MD must) (VP (VB be) (ADJP (JJ equal) (PP (IN for) (NP (DT the) (NN atom) (S (VP (TO to) (VP (VB be) (ADJP (JJ neutral))))))))))))))))) (. .)))
Atoms are neutral so that means that the positive protons and the negative electrons must be equal for the atom to be neutral.
(ROOT (S (SBAR (IN Because) (S (NP (NNS atoms)) (VP (VBP have) (NP (NP (JJ equal) (NNS numbers)) (PP (IN of) (NP (NP (JJ positive) (NNS protons)) (CC and) (NP (JJ negative) (NNS electrons)))))))) (, ,) (NP (PRP they)) (VP (VBP possess) (NP (DT a) (JJ neutral) (NN charge))) (. .)))