An emission of green visible light from the Cu2+ ion. The literature reports emission of blue visible light from the Cu+ ion. Choose the statement(s) below that best explain this data. (Select all that apply.)

AThe Cu+ ion has a greater effective nuclear charge than the Cu2+ ion.

BIncreasing the effective nuclear charge on an ion results in energy levels that are closer together.

CIncreasing the effective nuclear charge on an ion results in the emission of higher frequency photons.

DIncreasing the effective nuclear charge on an ion results in the emission of shorter wavel