If a mineral has a daughter to parent ration of 3: 1 (three daughter atoms for every one parent atom), how many half-lives have passed since the mineral formed?

passing a magnet thought the

mixture , because iron gets attracted to magnet .

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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