Dear Student
1. If the atom have proton=6
neutron =6
then there will be the 6 positive charge on the atom, but if the atom is neutral then there will be
6 electron also on the atom with the 6 proton then total charge will be 6-6=0
2. If the atom have proton=6
neutron =8
then there will be the 6 positive charge on the atom,
Regards