Valence Bond Analysis of the Lone Pair Bond Weakening Effect for the X?H Bonds in the Series XH n = CH 4 , NH 3 , OH <... A Valence Bond Analysis of the Lone Pair Bond Weakening Effect for the X-H Bonds in the Series XHn = CH4, NH3, OH2, FH... D Lauvergnat,P Ma?Tre...