Answer:
Compared to an atom of C-12, an atom of C-14 has a greater <u><em>mass number.</em></u>
Explanation:
Each chemical element is characterized by the number of protons in its nucleus, which is called the atomic number Z. But in the nucleus of each element it is also possible to find neutrons, the number of which can vary. The atomic mass (A) is obtained by adding the number of protons and neutrons of a given nucleus.
The same chemical element can be made up of different atoms, that is, their atomic numbers are the same, but the number of neutrons is different. These atoms are called element isotopes.
So, in this case C-12 and C-14 are two isotopes of the element carbon. Taking into account the aforementioned, then the difference between C-12 and C-14 is the number of neutrons in each of its atoms because the number of protons (atomic number) is 6 for both isotopes. So, atoms of C-12 have 6 neutrons and atoms of C-14 contain 8 neutrons.
Because neutrons have a mass comparable to that of protons, isotopes have a different atomic weight. Isotopes that have less neutrons are lighter and are called lighter isotopes, those with more neutrons weigh more and are called heavy isotopes. Then, C-12 is lighter than C-14.
<u><em>Compared to an atom of C-12, an atom of C-14 has a greater mass number.</em></u>
