Hello!
In this equation, the element we are working with is C, which is carbon. The number 6 represents the atomic number, and 13 is the atomic mass.
We know that the number of elections are equal to the atomic number, and the number of protons are also equal to the atomic number.
While, the number of neutrons are determined by subtracting the atomic mass by the atomic number.
13 - 6 = 7 neutrons
Therefore, there are 6 protons, 6 electrons, and 7 neutrons.