Here's why:

* Atomic Number: The number of protons in an atom defines its atomic number. Potassium has an atomic number of 19.

* Mass Number: The number of protons and neutrons together make up the mass number. In this case, the mass number would be 19 (protons) + 22 (neutrons) = 41.

Therefore, the element with 19 protons and 22 neutrons is potassium-41 (⁴¹K).