The element with 19 protons, 20 neutrons, and 19 electrons is Potassium (K).

Here's why:

* Protons define the element: The number of protons in an atom's nucleus determines what element it is. Potassium has 19 protons, making it potassium.

* Neutrons affect the isotope: The number of neutrons can vary within an element, creating different isotopes. This specific potassium atom is likely Potassium-39, as 19 protons + 20 neutrons = 39.

* Electrons balance the charge: In a neutral atom, the number of electrons equals the number of protons. This ensures the atom has a neutral charge.

Let me know if you have any other element questions!