( ( These ( outermost electrons ) ) ( ( are ( called ( valence electrons ) ) ) . ) )
(ROOT (S (NP (DT These) (NN outermost) (NNS electrons)) (VP (VBP are) (VP (VBN called) (NP (JJ valence) (NNS electrons)))) (. .)))
These outermost electrons are called valence electrons .
(ROOT (S (NP (NP (NNS Electrons)) (PP (IN in) (NP (NP (DT the) (JJ outer) (NN energy) (NN level)) (PP (IN of) (NP (DT an) (NN atom)))))) (VP (VBP are) (VP (VBN called) (NP (JJ valence) (NNS electrons)))) (. .)))