( ( ( ( Atoms ( that ( have gained ) ) ) or ) ( lost electrons ) ) ( ( are ( called ions ) ) . ) )
(ROOT (S (NP (NP (NP (NNS Atoms)) (SBAR (WHNP (WDT that)) (S (VP (VBP have) (VP (VBN gained)))))) (CC or) (NP (VBN lost) (NNS electrons))) (VP (VBP are) (VP (VBN called) (NP (NNS ions)))) (. .)))
Atoms that have gained or lost electrons are called ions .
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (DT an) (NN atom)) (VP (VBZ gains) (CC or) (VBZ loses) (NP (DT an) (NN electron))))) (NP (PRP it)) (VP (VBZ becames) (NP (DT a) (PRN (-LRB- -LRB-) (NP (NN n)) (-RRB- -RRB-)) (NN ion))) (. .)))