Answer:
B) Protons and Neutrons
Explanation:
In every atom, there is a Nucleus which contains protons and Neutrons. Protons being positive and Neutrons not having a charge (neutral).
<span>nuclear symbol consists of three parts: 1. the symbol of the
element; 2. the atomic number of the element;3. the mass of the element. for
the above problem, the symbol for potassium is k. it's atomic number is 40. the
number of protons is 19. so we denote this in the following nuclear symbol; 40
k 19</span>
The answer is D, medical diagnosis