The number of protons in an atom is equal the atomic number (= 50)
The sum of the Neutrons and Protons is the Atomic Mass (=125)
Neutrons + Protons=125
Plug in for the protons (50)
Neutrons +(50)=125
Then, once solved, we have Neutrons = 75
Assuming the atom is NOT an ion, the amount of electrons is equal to the number of protons. (protons=electrons=50=50)
Therefore:
There are 50 electrons, 50 protons, and 75 electrons.
