Answer:
The coefficient tells you how many molecules of that substance there is. The subscript tells you what the substance it. It tells you the the amount of each element there are in the molecule. Changing it would change the substance itself.
It's not chemical because it would have to react to something to change so it is physical change because it is the same thing but it just smells I hope this helped
True ^^ they explained it well
Answer:
D. Na2O
Because we already know that sodium oxide is a binary ionic compound because it contains one metal cation and one non-metal anion.
