Ionic bond is formed by electrostatic interaction between opposite charges like when a negatively charged atom comes close with positively charged atom then it forms the ionic bond.
In an ionic bond, the atom that loses the electron becomes positively charged and the atom that gains the electron becomes negatively charged. In an ionic bond, the electrons are shared unequally between two atoms while in a covalent bond is formed with equal sharing of electrons.
Therefore the correct answer is ionic bond will form between a slightly positive hydrogen atom in one molecule and a slightly negative atom in another molecule.
