The nickel atomic nucleus contains 28 protons and the copper atomic nucleus contains 29 protons.
Nickel atoms have 28 protons in their atomic nuclei, giving nickel the atomic number 28. In addition to 28 protons, a nickel atomic nucleus contains 30 to 36 neutrons, depending on the isotope.
Copper atoms have 29 protons in their atomic nuclei, which gives copper it atomic number 29. The atomic nuclei of copper also include 34 to 37 neutrons, depending on the isotope.