No of protons – 29
No of neutrons – 35
No of electrons – 29
Since the atomic number of copper is 29, the number of protons equals 29 as well.
Since the atom is neutral, the number of electrons is the same as the number of protons.
In order to find the number of neutrons, we have to find the atomic weight of copper (it’s 64)
Since the atomic weight = neutrons + protons, the number of neutrons = 64 – 29 = 35