2 isotopes of copper that occur naturally; 63Cu and 65Cu. The 63Cu atoms have a mass of 62.929601 amu and the 65Cu atoms have a mass of 64.927794 amu. What is the percent natural abundance for each isotope?

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.

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you need to have a picture of the atom that way we can answer it