A) Since both are carbons with the only difference in the number of neutrons,
They are called Isotopes
B) Carbon - 12 has 6 protons and 6 neutrons, while Carbon-13 has 6 protons and 7 neutrons,
Therefore Carbon-12 and Carbon-13 have the same number of protons
C) Carbon - 12 has 6 protons and 6 neutrons, while Carbon-13 has 6 protons and 7 neutrons,
Therefore Carbon-12 and Carbon-13 has different numbers of neutrons
D) Sorry i don't know any uses of Carbon-12 and Carbon-13, you might have to research to get it.
E or F) Sodium 23 has 12 neutrons and 11 electrons, because its mass number 23, atomic number is 11 and since protons and electrons count is same, the number of neutrons = mass number - atomic number = 23 - 11 = 12 neutrons
Happy to help :)
If you need any more help, feel free to ask
