Hydrogen Bonds Make Water Sticky
Water has an amazing ability to adhere (stick) to itself and to other substances.
Hydrogen Bonds
Hydrogen bonds form when hydrogen atoms covalently bonded to nitrogen (N), oxygen (O),
or fluorine (F) in the form of covalent compounds such as ammonia (NH3), water (H2O) and
hydrogen fluoride gas (HF). In these molecules, the hydrogen atoms do not pull as strongly
on the shared electrons as the N, O, or F atoms. Therefore, the molecules are polar; the
hydrogen atoms become positively charged and are able to form hydrogen bonds to negative
ions or negatively charged parts of other molecules (such as the N, O, and F atoms that
become negatively charged in these compounds).
Hydrogen bonds are not true bonds like covalent bonds or ionic bonds. Hydrogen bonds are
attractions of electrostatic force caused by the difference in charge between slightly positive
hydrogen ions and other, slightly negative ions. These attractions are much weaker than true
ionic or covalent bonds, but they are strong enough to result in some interesting properties.
Hydrogen bonds shown as the dotted lines between water molecules.
In the case of water, hydrogen bonds form between neighboring hydrogen and oxygen atoms
of adjacent water molecules. The attraction between individual water molecules creates a
bond known as a hydrogen bond.
A molecule of water has two hydrogen atoms. Both of these atoms can form a hydrogen bond
with oxygen atoms of different water molecules. Every water molecule can be hydrogen
bonded with up to three other water molecules. However, because hydrogen bonds are
weaker than covalent bonds, in liquid water they form, break, and reform easily. Thus, the
exact number of hydrogen bonds formed per molecule varies.
