Carbon-12 and carbon-13 are isotopes of carbon. Which of the following statements is correct?

They both have seven protons in the nucleus.

They both have the same mass number.

They both have seven neutrons in the nucleus.

They both have the same atomic number.

Carbon-13 has 7 neutrons and carbon-12 has 6 neutrons. Carbon-12 is the most common isotope of carbon. Carbon - 14 is radioactive and very rare. The symbols for the isotopes of carbon atoms shown here indicate they each have six protons but mass numbers of 14, 13 and 12.

They both have seven protons in the nucleus.