Question

copper contains how much electron

Answer 1

The number of protons in an atom of an element is the same as the atomic number. So finding the number of protons in an atom just consists of looking at a periodic table. Copper's atomic number is 29, so it has 29 protons. In a neutral atom, the number of electrons will equal and balance the number of protons, so it would also be 29 electrons. The number of neutrons will depend on the isotope you have. Atoms of the same element can exist with different numbers of neutrons - these are what we call isotopes. However, there are only two isotopes of copper, 63Cu and 65Cu, which have 34 and 36 neutrons respectively.