A student places a 3.45g iron nail into a beaker containg a copper(2) sulphate (CuSO4) solution.after the nail has completely reacted, there is a quantity of copper metal remaining at the bottom of the beaker. the student finds the mass of the recovered copper to be 3.73g. Determine the percentage yield?

The ground state is the lowest energy state of an atom while the excited state is any state that is higher than the ground state. Since the ground state configuration of Ga is 2-8-18-3 then the electron configuration of Ga in an excited state is represented by 2-8-17-4. In order to achieve the excited state an electron has to be promoted.