What is the total charge of the nucleus of a carbon atom?

The total charge of the nucleus of a carbon atom is $+ 6$.
Carbon has atomic number $6$ on the periodic table. This is because all carbon atoms have $6$ protons in their nuclei. Every proton has a +1 charge. Carbon atoms also have neutrons in their nuclei, numbering from $6 - 8$. However, neutrons have no charge. So the total charge of the nucleus of a carbon atom is $\text{+6}$.