Answer:
2-0-1, 1-1-1, 0-1-2, but they must all equal 3 electrons in total
Explanation:
In decomposition, two or more reactant combine to form one product only.
Answer: Y and Z. It's D.
Explanation: W represents evaporation, which is a physical change. X represents dissolving, which is also a physical change. If X and W aren't chemical changes, then Y and Z must be if half of the choices are.