The atmosphere is composed of
a. the oceans
b. the air within 500 feet of the earth's surface
c. all the gases that surround the earth
d. all the plants and animals that breathe the gases that surround the earth.

the product of the pressure and volume is also constant

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.

if it's not useful, feel free to report for mistake in answer.