For the exothermic reaction 3h2(g)+n2(g)→2nh3(g) which of the following changes could be carried out in such a way as to not cause the reaction to shift either to the left or to the right?

a) raising the temperature and removing nh3
b) lowering the temperature and adding nh3
c) both a or b
d) neither a or b

your picture is not part of the scientific method.

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.