In a sample of the element potassium, what does each atom contain?
Have you got a Periodic Table........?
An atom of potassium contains PRECISELY 19 protons, 19 massive, positively charged
Within the nucleus there are also about 20 neutrons, 20 massive particles with ZERO charge. The neutrons and protons engage in the strong nuclear force, which, at such short internuclear ranges, engage in the strong nuclear force, that is sufficient to overcome the electrostatic repulsion that would tend to force the protons apart.
The presence of 20 or 21 or 19 neutrons within the nucleus gives rise to the phenomenon of