( ( ( ( ( ( The ( third atom ) ) ( is ( ( Lithium ( -LRB- ( Li -RRB- ) ) ) ( with ( ( ( three protons ) and ) ( three electrons ) ) ) ) ) ) and ) so ) ( it ( goes on ) ) ) . )
(ROOT (S (S (NP (DT The) (JJ third) (NN atom)) (VP (VBZ is) (NP (NP (NP (NNP Lithium)) (PRN (-LRB- -LRB-) (NP (NNP Li)) (-RRB- -RRB-))) (PP (IN with) (NP (NP (CD three) (NNS protons)) (CC and) (NP (CD three) (NNS electrons))))))) (CC and) (RB so) (S (NP (PRP it)) (VP (VBZ goes) (PRT (RP on)))) (. .)))
The third atom is Lithium (Li) with three protons and three electrons and so it goes on.
(ROOT (S (NP (NNP Lithium)) (VP (VBZ has) (NP (CD three) (NNS electrons))) (. .)))