2. Correct. The answer is true. A U B means the 'union' of sets A and B. The union of A and B is a set which elements belong to either A or B or both. Graphically, the Venn diagram is:

 

Since A = { Au, Ag, Cu} and B = {Iron (Fe), Cobalt (Co), Nickel (Ni), Copper (Cu), Zinc (Zn)}, then AUB = {Fe, Co, Ni, Cu, Zn, Au, Ag }.