p+ = 6
n0 = 6
e- = 6
amu = 12
EXPLANATION: Carbon has atomic number equal to 6, and the atomic number of an atom is equal to the number of protons and is also equal to number of electrons for an atom.
While mass number of carbon's most stable isotope is 12. mass number is equal to no. of protons plus no. of neutrons. So to calculate no. of neutrons we subtract no. of protons from mass no., i.e. (12-6), which comes equal to 6 for carbon. so, n0 = 6.