Answer the following question given this paragraph: 

Nuclear chemistry is the study of reactions that involve changes in nuclear structure. The chapter on atoms, molecules, and ions introduced the basic idea of nuclear structure, that the nucleus of an atom is composed of protons and, with the exception of 11 H, neutrons. Recall that the number of protons in the nucleus is called the atomic number (Z) of the element, and the sum of the number of protons and the number of neutrons is the mass number (A). Atoms with the same atomic number but different mass numbers are isotopes of the same element. When referring to a single type of nucleus, we often use the term nuclide and identify it by the notation A where X is the symbol Z X, 14 ⎞ Often a nuclide is referenced 6 C⎠. example, 146 C is called “carbon-14.


Q: Atoms with the same atomic number but different mass numbers are called what?

 Choices:

- tropes

- organisms

- reactions

- isotopes

A:
isotopes
