# How many, and what type of nuclear particles occur in ""^12C, ""^13C, and ""^14C?

Well, their nuclei all contain 6 protons, massive, positively charged nuclear particles. The standard ""^12C isotope also contains 6 neutrons, 6 massive, neutrally charged nuclear particles. A smaller percentage contains 7 neutrons, to give the ""^13C isotope, which is a very important isotope for NMR experiments, and an even smaller percentage contains 8 neutrons to give ""^14C.