May be the instrument is incorrect or may be error in it.
Explanation:
The copper have not been detected by this test because the test may be not for the detection of copper, may be it is used for identification of another minerals. If there is copper in the lake sample but can't be detected in the test so it means that the instrument which is used for detection is not the right one or having error in that instrument. Every mineral has a specific type of instrument that detect its presence, if we use incorrect instrument for the mineral then we can't detect the presence of that specific mineral.
Chris is correct because the reactants and products do not have to have the same mass, but they do have to weigh the same. Is the correct answer:) Hannah is right because the mass of the reactants was different than the mass of the products. is incorrect
I think you forgot to give the options along with the question. I am answering the question based on my research and knowledge. "<span>You should remove heat energy because air is a gas and particles need to slow to become a liquid" is the way you can make water for drinking in the desert. I hope it helped you.</span>
