Final answer:
An atom of nickel contains 28 electrons, which is equal to its atomic number. The atomic number represents the number of protons, and in neutral atoms, the electron count is the same. Nickel has a mass number of 59 in a certain isotope, meaning 31 neutrons are also present.
Step-by-step explanation:
There are 28 electrons in an atom of nickel. This is because the atomic number of nickel, which is 28, signifies the number of protons in the nucleus of the atom, and in a neutral atom, the number of electrons is equal to the number of protons. The atomic mass of nickel is 58.7, and apart from electrons and protons, a nickel atom also contains neutrons. With reference to a particular nickel isotope with a mass number of 59, it will contain 31 neutrons as well.
The concept of coordination number pertains to the crystal structure of metals, and in the case of nickel, which crystallizes in a cubic closest packed structure, the coordination number would be 12. This refers to the number of nearest neighboring atoms to a nickel atom in the crystal lattice.