Answer:
18.3%
Explanation:
Add the numbers together, and then take the number of grams of the substance, in this case copper, not coppper lol. divide the .45 by 2.45 to get 18.3
If it is shown as ∆H , then it means that a specific chemical reaction is undergoing heat in Kelvin(K). If it is shown as ∆H° , then it means that a specific chemical reaction is undergoing heat in Celsius(C⁰).
Hope this is the answer you are looking for mate!
If it is correct then please mark my answer as the brailiest! :)
Melting (solid to liquid)