( ( ( ( ( Usually ( atoms ( have ( ( equal numbers ) ( of ( ( ( ( protons and ) electrons ) , ) ( which ( means ( that ( they ( ( are electrically ) neutral ) ) ) ) ) ) ) ) ) ) ) , ) and ) ( therefore ( normally ( ( no ( electric forces ) ) ( are present ) ) ) ) ) . )
(ROOT (S (S (ADVP (RB Usually)) (NP (NNS atoms)) (VP (VBP have) (NP (NP (JJ equal) (NNS numbers)) (PP (IN of) (NP (NP (NNS protons) (CC and) (NNS electrons)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBZ means) (SBAR (IN that) (S (NP (PRP they)) (VP (VBP are) (ADVP (RB electrically)) (ADJP (JJ neutral))))))))))))) (, ,) (CC and) (S (ADVP (RB therefore)) (ADVP (RB normally)) (NP (DT no) (JJ electric) (NNS forces)) (VP (VBP are) (ADJP (JJ present)))) (. .)))
Usually atoms have equal numbers of protons and electrons, which means that they are electrically neutral, and therefore normally no electric forces are present.
(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))) (. .)))