Battery Chemistry /98 Electrochemical reaction >A pair of redox reactions between elements at the two electrodes that involves the change of valence state > Oxidation at anode.reduction at cathode ●Free electrons > Free electrons are generated by the reactions at the electrodes ●Complete circuit > Electrons flow through the outer circuit to power up the external loads 99 Battery Chemistry  Electrochemical reaction  A pair of redox reactions between elements at the two electrodes that involves the change of valence state  Oxidation at anode, reduction at cathode  Free electrons  Free electrons are generated by the reactions at the electrodes  Complete circuit  Electrons flow through the outer circuit to power up the external loads