Answer:
The mass percent of copper as element is the same.
Explanation:
First of all we need the reaction that is presented below:
→ 
The mass percent of copper (Cu) as element is the same because of during the reaction the element only transform its nature from copper carbonate (
) to copper oxide (
), the latter is a solid and will remain in the system.
On the other hand, you will note that the global percentage mass will be small because of the reaction produce (
) that is a gas and this one will escape for the system.
Have a great day!
Explanation:
Sydney has been the work that is a great place 56 to be able and a day and day for a week or two types and we will have a very nice time of course but 6yy6667 has 7575665yy44y
the numbers are going to be small so like a power but its at the bottom
NH3, H2O2, NHO2
I believe your answer would be the first one
hope this helps