It doesn't have a single atomic number because it's a compound, not an element.
Here's why:
* Atomic number: The atomic number represents the number of protons in an atom's nucleus, defining an element.
* Pyrite: Pyrite is composed of two different elements: iron (Fe) and sulfur (S).
Iron (Fe) has an atomic number of 26.
Sulfur (S) has an atomic number of 16.
You can't assign a single atomic number to a compound like pyrite.
