Question: 

Of the three types of "elementary particles" constituting atoms, determine which type(s) influence the following properties of an element:

1. The chemical identity of the atoms (whether it is an atom of nitrogen, iron, silver, or some other element).
2. The mass of the atom.
3. The electrical charge of the atom. Whether or not it is radioactive (spontaneous disintegration of the nucleus).

Answer:

1. The chemical identity of the atoms: protons.
2. The mass of the atom: neutrons and protons, and to a much lesser extent, electrons.
3. The electrical charge of the atom: electrons and protons (whether or not the numbers are equal).
   
4. Whether or not it is radioactive: neutrons, although one might also say protons in some cases, as there are no known "stable" (non-radioactive) isotopes of certain elements, the identity of an element being determined strictly by the number of protons.