Question

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.

Answer 1

Number of protons is the exact same thing as the identity of an atom. 1 proton is hydrogen, 2 protons is helium, etc.

Electrons are so tiny, that we only consider protons and neutrons which have about the same mass to measure the weight.

Atomic number is the same thing as number of protons.

Answer 2

Thank you so much.(: