( ( Since ( ( electronegative groups ) ( decrease ( the ( electron density ) ) ) ) ) ( , ( there ( ( will ( be ( less ( ( shielding -LRB- ) ie ) ) ) ) . ) ) ) )
(ROOT (S (SBAR (IN Since) (S (NP (JJ electronegative) (NNS groups)) (VP (VB decrease) (NP (DT the) (NN electron) (NN density))))) (, ,) (NP (EX there)) (VP (MD will) (VP (VB be) (VP (ADVP (RBR less)) (VBN shielding) (-LRB- -LRB-) (NP (NN ie))))) (. .)))
Since electronegative groups decrease the electron density, there will be less shielding (ie.
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (PRP we)) (VP (VBP move) (PRT (RP down)) (NP (NP (DT a) (NN group)) (PP (IN of) (NP (NNS elements)))) (PP (IN on) (NP (NP (DT the) (JJ periodic) (NN table)) (, ,) (NP (PRP$ their) (NN electronegativity))))))) (NP (PRP it)) (VP (VBZ decreases)) (. .)))