Aluminum foil, cast iron pans, copper pipes, graphite, and sea water can be classified as A)insulators because free electron flow is hindered by the structure of the material.
Eliminate
B)conductors because electrons can move freely from one atom to another creating a current.
C)superconductors because they provide no resistance to electron flow through the material.
D)semiconductors because electron movement is dependent on the conditions - such as temperature and voltage.