What is the nuclide symbol for carbon 13?

The nuclide symbol for Carbon-13 is 13C6, where 13 is written in superscript and 6 in subscript. This means that Carbon-13 has 13 nucleons, six protons and the chemical symbol C. In an alternative notation, the number 6 could be placed on the left of the letter C.

A nuclide symbol contains the symbol of the chemical element in question together with the number of protons and the number of nucleons (protons and neutrons) in the system. The number of protons is also known as the atomic number, and the number of nucleons is also known as the mass number.