Answer:
B. water displacement is used "graduated cylinder is filled with water (100 mL) and the object is then put inside. ... If the new water level is (120 mL) we now know that the object has a volume of 20 mL."
Explanation:
You could use another word for change can be variable witch means change and if you times the one two more times then you would get four because two time two would be four and times the one would be four.
I think its c, it makes sense to me to be c
So the unbalanced equation would be Mg + N^2 --> Mg^3N^2
Which means the balanced equation would be 3Mg + N^2 --> Mg^3N^2
This is balance the equation out since you now has 3 magnesium and 2 nitrogen on the left side, and 3 magnesium on 2 nitrogen on the right. Double check my work though, it's been awhile.
