Are the following materials atoms, molecules, or both?
a. carbon
b. water
c. carbon dioxide
d. nitrogen

A molecule has all valencies covered by molecular (covalent) bonds, leaving no unpaired electrons. A carbon atom needs to form four bonds, and can not be considered a molecule by itself. Buckminsterfullerene, a “sphere” made of sixty carbon atoms, is a molecule completely consisting of carbon atoms.

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.

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

i think it's c. if you look search electronic symbol on google and then click on wiki it shows you a