Most atoms have more neutrons than protons which accounts for basically half of the nucleuses mass.
So,
Formate has a resonating double bond.
In molecular orbital theory, the resonating electrons are actually delocalized and are shared between the two oxygens. So the carbon-oxygen bonds can be described as 1.5-bonds (option B). I'm not sure if option C is correct, however, because the likelihood of both delocalized electrons being in the area of one oxygen atom is less than 50%.<span />
<span>Water molecules form a complex with metal ions (usually a 6-coordinate complex). And the high charge density on a metal ion draws electrons away from the water molecules, making the O-H bonds more polar than normal. This allows the dissociation of the protons, making solutions of most metal ions acidic</span>
