In an atom, there are three most known subatomic particles. These are protons, neutrons, and electrons. Both the protons and neutrons are located inside the nucleus and make up almost all of the masses of the atom. The electrons, on the other hand, are outside the nucleus.
In a neutral atom, the number of electrons and protons are equal. In this item, it is not given that the atom is either charged or not. It is then assumed that the element is neutral. Hence, the number of protons is also equal to 47. This element is silver (Ag). The isotope of the silver which contains 68 neutrons is Ag-115.
ANSWER: Ag-115
