One thing that does not change is the chemical composition of water, which is still H2O. And maybe mass, if all of the particles remain inside the beaker, which was never mentioned in the question so I am not sure.
Answer:
Cu
Explanation:
In the given reaction of the addition of copper to nitric acid,
Cu(s) + 4HNO3(aq) -> Cu(NO3)2(aq) + 2NO2(g) + 2H2O(l)
Cu or copper would be characterized as the reducing agent in this reaction. It is the chemical substance that is losing electrons and being oxidized due to this reduction/loss in this redox reaction as it is the metal that loses electrons by reacting with the non-metals.
Answer:
1.) 3
2.) 60 CM
Explanation:
1. Density=
= 
2. Length*Width*Height=3*10*2
