If a carbon atom is bonded to two hydrogen atoms and two carbon atoms

That molecule is a propane.

Explanation:

Look at the scheme

H3C     H    

                   C

H3C     H

C3H8

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.

it takes on an electronical energy