Here's why:

* Oxygen has two lone pairs of electrons: These lone pairs can interact with hydrogen atoms that are covalently bonded to other electronegative atoms like nitrogen or oxygen.

* Hydrogen bonding: This interaction is called hydrogen bonding and is a strong type of intermolecular force. It's important for things like the structure of water, DNA, and proteins.

Let me know if you'd like to know more about hydrogen bonding!