Here's why:

* Atomic Number: The atomic number represents the number of protons in an atom's nucleus. This number defines what element the atom is.

* Carbon: All carbon atoms have 6 protons.

* Carbon-14: The number "14" in carbon-14 refers to the atomic mass, which is the total number of protons and neutrons in the nucleus. Carbon-14 has 8 neutrons (6 protons + 8 neutrons = 14).

Even though carbon-14 has a different number of neutrons compared to the most common carbon isotope (carbon-12), it still has the same number of protons and therefore the same atomic number.