Why are people concerned with an increase in carbon dioxide in our atmosphere?

Carbon dioxide concentrations are increasing mostly because of the fossil fuels that people are burning for energy, not to mention it is causing global warming.

Explanation:

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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