How Do Protons Determine the Identity of An Element? Should They?

OP: As I understand it, the only thing on a chemical level differentiating the different elements from each other is number of protons, and thus electrons. But how does adding one proton change something from say, carbon to nitrogen?

I’ve had awhile to think about this since I first posted this thread…

I suspect Van Der Waals forces might play a critical role in elemental identity.

The basic chemistry books in high school basically teach that all the action in the atom takes place in the electron orbitals.
So why would identity be determined by number of protons.

In fact, the protons in the core do exert a pull on other atoms known as Van der Waals forces. Perhaps this is one source of an element’s unique properties that’s directly influenced by number of protons?