Question

carbon - 12 and carbon - 13
a both have the same number of protons
b both have the same number of neutrons
c have the same atomic mass
d have different electron configurations

Explanation:

Carbon - 12 and carbon - 13 are isotopes of carbon. Isotopes of an element have the same number of protons (which defines the element, carbon has atomic number 6, so 6 protons for both). The number of neutrons is different (carbon - 12 has \(12 - 6=6\) neutrons, carbon - 13 has \(13 - 6 = 7\) neutrons). Atomic mass is different (12 and 13 respectively). Electron configuration depends on the number of electrons, which for neutral atoms is equal to the number of protons. Since protons are the same, electron configuration is the same.

Answer:

A. Both have the same number of protons