# if the shared electrons in covalent bond revolves around their nucleus, how they hold the two molecules together? [duplicate]

Let's consider a simple case, $\ce{H2}$. When the two nuclei come closer to each other (starting from a long distance), the electrons benefit in terms of energy because they now enjoy being attracted to two nuclei instead of just one. This energy gain is (partly) responsible for the bond dissociation energy, which needs to be invested in order to break the bond again. For a discussion on why the nucleus-electron interaction outweighs the electron-electron repulsion, see this question.