Sulfur and argon do not have the same atomic number. The atomic number of an element is the number of protons in the nucleus of an atom of that element. Sulfur has an atomic number of 16, which means that each atom of sulfur has 16 protons in its nucleus. Argon has an atomic number of 18, which means that each atom of argon has 18 protons in its nucleus. Therefore, sulfur and argon have different atomic numbers.