Which reaction would occur at the anode in a voltaic cell? Mg(s)→Mg2++2e−

Cd2+(aq)+Zn(s)→Zn2+(aq)+Cd(s)

K+(aq)+e−→K(s)

Cu2(aq)+2e−→Cu(s)

Select the correct answer from each drop-down menu. to make a table of the elements, dmitri mendeleev sorted the elements according to their . he then split the list of elements into several columns so that elements beside each other had similar .