I anm definitely not a halogen. But if all you knew about me was my atomic mass (not my atomic number or properties).
then you might expect me to be located one element over in
the halogen family. Who am I?

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