Answer:
D atoms of the same element which have different numbers of neutrons
Step-by-step explanation:
Isotopy is the existence of two or more atoms of the same element having the same atomic number but difference mass number due to differences in the number of neutrons in their various nuclei.
- These atoms are called isotopes
- Isotopes of an element have the same electronic configuration.
- They have the same chemical properties but only differ in their masses due to the difference in the number of neutrons.