What is hydrogen bonding?

Hydrogen bonding is a type of chemical interaction, or bond, that occurs between certain types of molecules. Hydrogen bonding relies on a chemical concept known as polarity. Just as the name suggests, polarity in chemistry refers to two ends of a molecule having opposite charges; one end is positive and the other end is negative resulting in a polar molecule. Let's illustrate this with an example molecule: water (I will illustrate this by drawing). The key facts that you need to keep in mind about the water molecule are: (1) a water molecular consists of two Hydrogen atoms bonded to an Oxygen atom, and (2) the overall structure of the molecule is bent – this is because the Oxygen atom has another 2 pairs of unbound electrons which take up space around the atom.Oxygen is more electronegative than Hydrogen – this means it is greedier for electrons – and it essentially hogs the electrons from the much smaller Hydrogen atoms. This gives the Oxygen a partial negative charge, and the Hydrogen atoms a partial positive charge. As a result the whole molecule is polar.This leads to hydrogen bonding. The positive end of one water molecule will be attracted to the negative end of another (I will illustrate this by drawing). This phenomenon can occur any time a very electronegative atom is bonded to Hydrogen, including Fluorine and Nitrogen.