9.The land area of Greenland is 840,000 mi2 with only 132,000 mi2 free of perpetual ice. The average thickness of this ice is 5000 ft. Estimate the mass of ice to two significant figures. The density of ice is 0.917 g/cm3.

Explanation:

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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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answersilicon (si); oxygen (o);