Which equation is a reduction half-reaction that is written correctly?
zn2+(aq) + e– mc004-1.jpg zn(s)
be2+(aq) + 2e– mc004-2.jpg be(s)
2cl–(aq) mc004-3.jpg cl2(g) + 2e–
au(s) mc004-4.jpg au3+(aq) + 3e–

when [oh-] is 10-5  m, and [h3o+] is 10-9  m, the poh is 5 and ph is 9. again in both cases the sum of ph and poh is 14. however, the hydrogen ion concentration is not always going to be equal to exactly 1 x 10 raised to a negative number. for example, we skipped over the value of 2.0 x 10-7.

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.