* Nitrogen (N): Nitrogen typically forms three bonds (trivalent), and its most common oxidation states are -3, +3, and +5.

* Chlorine (Cl): Chlorine typically forms one bond (monovalent) and has a common oxidation state of -1.

To have a neutral compound, the charges of the elements must balance. The formula N7Cl3 would require an extremely unusual arrangement of bonds and oxidation states that is unlikely to be stable.

Possible Misunderstandings:

* Typo: It's possible there was a typo in the formula. Double-check the original source.

* Uncommon compound: It's extremely rare for a compound to have such high numbers of atoms of a single element.

If you can provide more context about where you encountered this formula, I may be able to offer a more specific explanation.