Answer:
D. THEY HAVE THE SAME NUMBER OF PROTONS AND ELECTRONS BUT DIFFERENT NUMBERS OF NEUTRONS.
Step-by-step explanation:
Isotopy is the phenomenon that explains the various variants of an element having different number of neutrons but the same number of protons and electrons.
Isotopes are variants of a particular chemical element that possesses the same number of proton or atomic number but different mass number. The atomic number of an element is the number of protons and electrons contained by the element while the mass number is the sum total of the number of protons and neutrons in the nucleus of the elements.
Examples of isotopes are the hydrogen atom, chlorine element and so on.
Hydrogen has three isotopes which are hydrogen H, Deuterium and Tritium. Chlorine has two isotopes which are chlorine 35 and chlorine 37.
So the true options about isotopes is that they possess the same number of protons and electrons but different numbers of neutrins.