The hydrogen bond concept presents three different circumstances: 1) when electrons are shared between two atoms; 2) when there is an attractive force between an atom with a negative electrical charge of one molecule and a hydrogen atom covalently bonded to another negative atom of another molecule ; 3) when an atom picks up electrons from another atom. Hydrogen Bridge
In this way, it can be said that the hydrogen bond is the force of attraction between an electronegative atom of a molecule with a hydrogen atom covalently bonded to another electronegative atom in a nearby molecule .
The hydrogen bridge in the case of water
The hydrogen bond is the result of the formation of a force with a hydrogen atom bonded to a nitrogen, oxygen or fluorine atom, which are especially electronegative atoms and hydrogen bond acceptors, regardless of whether they are covalently bonded to a hydrogen atom. Hydrogen Bridge
In this sense, water is a covalent molecule that has hydrogen bonds between the atoms of one molecule and the oxygens of the next molecule , for this reason water forms networks of unique properties. Thus, if there were no connection hydrogen in water could not be explained its point of boiling higher or its surface tension.
Intermolecular bonds constitute the interactions between individual molecules of a substance. From these interactions it is possible to explain the properties of liquids (eg boiling point) and solids (eg melting point).
There are three intermolecular bonds: the dipole-dipole bond, the hydrogen bond and the dispersion forces .
The dipole-dipole bond refers to the positive and negative polar molecules that interact and establish an electrical attraction force with each other. The hydrogen bond is a type of dipole-dipole bond, which occurs between polar molecules, but with a particular characteristic : these polar molecules need a hydrogen that is bonded to other elements of high electrical negativity, such as fluorine , oxygen and nitrogen. Hydrogen Bridge
Finally, scattering forces, also known as London forces, are weaker than the two previous forces and have an important characteristic: they are forces that settle between nonpolar molecules, that is, those that do not have poles or electrical charges. (the attraction is produced even without an electrical charge), since a non-polar molecule induces the dipole of another molecule, causing an intermolecular bond, as happens with non-polar gases after a change from gas to liquid through liquefaction. Hydrogen Bridge