Hypothesis: If a material undergoes a chemical change, then it will not retain its original properties because a new substance is formed. To test the hypothesis above, you will observe the changes during the experiment. To do this, you will use these observations to compare the of the substances to the of the substances.

the correct answer is:

a. formation of precipitation

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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