**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 }.