Two molecules of mercury oxide decompose into 2 molecules of mercury and 1 molecule of oxygen gas. Which of the following equations correctly describes this reaction? Select one:
a. A
b. B
c. C
d. D

This one's pretty simple. Mc and Pr aren't even actual elements. The symbol for Mercury is Hg, Mn is Manganese.

The correct answer would be D

2 moles of HgO decomposing (essentially splitting apart into their original elements) into 2 moles of Hg and 1 mole of O2 (Oxygen is a diatomic molecule meaning it always has 2 of itself attached, and O2 is always in its gaseous form)

the answer is barium and copper bromide

colorless gas, exhibiting a blue glow when placed in an electric field

b) solid

its a type of rock