In a polar covalent bond, a) electrons are not shared equally between atoms b) electrons are shared equally between atoms c) a cation is bonded to an anion d) electrons are transferred between atoms

I think 
A) electrons are not shared equally between atoms, because electron are shared but moved more toward  electronegative atom,but
maybe they would like more D)

Spontaneity tell us the direction of the reaction, but not how fast it goes. gibbs free energy brings together enthalpy, entropy and temperature in one easy formula. g = h - ts. and, finally the sign of delta g is always negative for a spontaneous reaction.