Sobre as rochas que compõem a crosta terrestre, análise a alternativa correta A)O arenito e o calcário são exemplos de rochas metamórficas B)As rochas magmáticas formaram-se pelo resfriamento e pela solidificação de minerais do manto terrestre, isto é, o magma C)As rochas são homogêneas e formadas por um único material D)As rochas metamórficas formaram-se a partir da compactação de sendimentos de outras rochas

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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