Jane is investigating to find out if bean plants grow taller in ordinary topsoil or special potting soil over a three week period. She sets up her investigation with 10 bean plants
of equal size in each type of soil.
What should Jane do each day to make sure she gets valid results?

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.

that's what i got you can count the number of atoms