You that Mg is the metal if in the periodic table it lands between group 1-12. So yeas Mg is a metal because it lands in group 2.
What do you mean by that Oh wait do you mean like 2×2=4 or 2+2=4 something like that maby?? I am still confused?? XD
Answer:
in prism
it's from the rectangular reflecting surface
S and O would be on a polyatomic ion as I know of