Hydrogen bond formation An atom X bond covalently .Hydrogen atom with hydrogen atom An atom Y form hydrogen bond with the hydrogen atom. A third atom cannot form hydrogen bond with hydrogen again as it experience large repulsion from other two atoms.Hydrogen bond formation X Y ？ An atom X bond covalently with hydrogen atom An atom Y form hydrogen bond with the hydrogen atom. A third atom cannot form hydrogen bond with hydrogen again as it experience large repulsion from other two atoms. Hydrogen atom