( ( The ( valence electron ) ) ( ( ( will only ) ( ( escape ( the atom ) ) ( if ( ( the electron ) ( is ( ( given ( ( an amount ) ( of energy ) ) ) ( ( ( equal ( to ( the ionization ) ) ) energy ) ( for ( that atom ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (JJ valence) (NN electron)) (VP (MD will) (ADVP (RB only)) (VP (VB escape) (NP (DT the) (NN atom)) (SBAR (IN if) (S (NP (DT the) (NN electron)) (VP (VBZ is) (VP (VBN given) (NP (NP (DT an) (NN amount)) (PP (IN of) (NP (NN energy)))) (NP (NP (ADJP (JJ equal) (PP (TO to) (NP (DT the) (NN ionization)))) (NN energy)) (PP (IN for) (NP (DT that) (NN atom)))))))))) (. .)))
The valence electron will only escape the atom if the electron is given an amount of energy equal to the ionization energy for that atom.
(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)))) (. .)))