( Electronegativities ( ( ( ( increase ( across ( period 3 ) ) ) and ) ( ( decrease down ) ( a group ) ) ) . ) )
(ROOT (S (NP (NNS Electronegativities)) (VP (VP (VB increase) (PP (IN across) (NP (NN period) (CD 3)))) (CC and) (VP (VB decrease) (PRT (RP down)) (NP (DT a) (NN group)))) (. .)))
Electronegativities increase across period 3 and decrease down a group.
(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)) (. .)))