Answer:
The answer is, in fact, Calcium Nitrate. I even looked it up to make sure, and according to PubChem, it is Calcium Nitrate. I suggest asking your teacher what this question is trying to ask because if it says it is not Calcium Nitrate, someone got it wrong.
Explanation:
The only other name I can think of, though, is Calcium Dinitrite.
Well, which weighs more? 2 tons of bricks or 2 tons of feathers? A lot of people would say bricks. But no, you just have to use a lot more feathers to equal the same weight. That is what you are looking for here. It weigh the same no matter what you put in it.
An Element, hope i helped out