How Many protons has 59CO?

Answer 1

Every Cobalt atom has the same number of protons.. 27. What can vary are the number of neutrons (to give a different molar mass and produce isotopes) or the number of electrons (to give a different electric charge and produce ions).

Answer 2

Lancenigo di Villorba (TV), Italy

Starting from the "radionuclide" 's question, in the first half of XX century, chemists introduced "Atomic Number" stating it is the Proton's number present in the nuclides.
Periodic table assign 27 as A.N. to Cobalt and its isotopes or nuclides.
The answer is 27.

I hope this helps you.