We just purchased a ceiling lamp at ikea to install in the old apartment we moved into. We removed the ceiling lamp that was there and found 3 black wires: 2 bound by tape to the wiring in the ceiling and one "grounded" on the screw that held up the fixture. The ikea lamp also has 3 wires: black, white and green. According to the ikea representative, the green is the "grounding" wire. Should we install the new lamp like the old one before? Black and white wires connected to the ceiling wires and green one on the screw? Should we just call and electrician? Thanks. Please excuse the ignorance...

There should be black and white wires that went to the old light fixture, and the green or bare ground wire. The fixture needs one hot and one neutral wire. If there is any question about what you have or how to connect this light, may be best to call in an electrician.