( Thus ( , ( electronegativities ( generally ( ( DECREASE ( as ( we ( ( ( ( ( move down ) ( ( a column ) ( in ( the ( Periodic Table ) ) ) ) ) , ) and ) ( INCREASE ( as ( we ( ( move ( from LEFT ) ) ( to ( RIGHT ( across ( the table ) ) ) ) ) ) ) ) ) ) ) ) . ) ) ) ) )
(ROOT (S (ADVP (RB Thus)) (, ,) (NP (NNS electronegativities)) (ADVP (RB generally)) (VP (VBP DECREASE) (SBAR (IN as) (S (NP (PRP we)) (VP (VP (VBP move) (PRT (RP down)) (NP (NP (DT a) (NN column)) (PP (IN in) (NP (DT the) (NNP Periodic) (NNP Table))))) (, ,) (CC and) (VP (VBP INCREASE) (SBAR (IN as) (S (NP (PRP we)) (VP (VBP move) (PP (IN from) (NP (NNP LEFT))) (S (VP (TO to) (VP (VB RIGHT) (PP (IN across) (NP (DT the) (NN table)))))))))))))) (. .)))
Thus, electronegativities generally DECREASE as we move down a column in the Periodic Table, and INCREASE as we move from LEFT to RIGHT across the table.
(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)) (. .)))