An atom with 18 neutrons and 17 protons in its nucleus has a nuclear charge.

The nucleus consists of positively charged particles – protons and negatively charged particles – electrons, which move around the nucleus in a specific orbital. In the same way, there are neutrons in the nucleus, they are neutrally charged and in order to calculate the number of neutrons it is necessary to subtract the ordinal number from the atomic mass (it is he who shows the number of protons and electrons).
If there are 17 protons, then the charge of the nucleus is +17, the number of electrons is also 17. The atomic mass is 17 + 18 = 35 g / mol. This atom is chlorine.