Hydrogen Bond

No, it’s not about 007 or anything like that. Hydrogen bond is a type of intermolecular (and sometimes intramolecular) bond that forms between an hydrogen and an electronegative atom (Nitrogen, Oxigen and Flourine). 

An example of intermolecular hydrogen bonding in aself-assembled dimer complex reported by Meijer and coworkers. The hydrogen bonds are the dotted lines. (Wikipedia).

Even though it might not be a very strong type of bonding it is extremely crucial for life as we know it. It is responsible for water’s physical properties and it is even in our DNA.