( ( energy level ) ( ( ( to ( ( the n ) ( = ( 1 ( energy level ) ) ) ) ) ( What ( ( frequency light ) ( is emitted ) ) ) ) ? ) )
(ROOT (FRAG (NP (NN energy) (NN level)) (PP (PP (TO to) (NP (NP (DT the) (NN n)) (SBAR (S (VP (SYM =) (NP (CD 1) (NN energy) (NN level))))))) (SBAR (WHNP (WP What)) (S (NP (NN frequency) (NN light)) (VP (VBZ is) (VP (VBN emitted)))))) (. ?)))
energy level to the n =1 energy level What frequency light is emitted?
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (NNS electrons)) (VP (VB return) (PP (TO to) (NP (DT a) (JJR lower) (NN energy) (NN level)))))) (, ,) (NP (PRP they)) (VP (VBP emit) (NP (NP (DT the) (JJ excess) (NN energy)) (PP (IN in) (NP (NP (DT the) (NN form)) (PP (IN of) (NP (NN light))))))) (. .)))