1. A student was given a mixture containing
copper oxide (insoluble) and copper sulfate
(soluble) and asked to separate them. Firstly,
she stirred the mixture into water, then filtered
it Next, she evaporated the filtrate.
a) What substance was the
residue in the filtration?
b) Describe what the filtrate was.

all eukaryotic cell have mitochondria : )

metals are good conductor of electricity. it has free electrons on their surface. according to electron pool theory, each atom present in a metal crystal losses all of its valence electron and as a result a pool of free is form. these pool of electrons are free to move and   conduct electricity easily   while making metal as good conductor.

the correct answer is a. the ability of electrons to flow throughout the metal.

if it's not useful, feel free to report for mistake in answer.