holadi

just the simple question--how would i determine which group would exert which type of electronic displacement effect on the+organic compound and ,moreover how will i determine whose effect would be dominant over others(suppose two grps have +i and -i on the ring or like chlorine which has +m as well as -i,so how would i determine which would be dominant).

like in ch3c6h5OH where ch3 is attached in para position with respect to OH in benzene how does this make it more stable alcohol than CH3 on ortho position?

why are they resonance hybrid considered to have a lower energy state than other resonance hybrid?does the delocaliazation of electrons cause?if yes then y? ..help me ASAp