The electrodes in a silver oxide battery are silver oxide \(\left(\mathrm{Ag}_{2} \mathrm{O}\right)\) and zinc. (a) Which electrode acts as the anode? (b) Which battery do you think has an energy density most similar to the silver oxide battery: a Li-ion battery, a nickelcadmium battery, or a lead-acid battery?

In a silver oxide battery, the redox (reduction-oxidation) reaction occurs between silver oxide (Ag2O) and zinc. During the chemical reaction in the battery, electrons will flow from one electrode to the other, creating a potential difference that can be used to power devices.

The anode is the electrode that undergoes oxidation, meaning it loses electrons. In the case of a silver oxide battery, the Zinc (Zn) electrode will lose electrons and will be oxidized to Zinc ion (Zn²⁺), thus acting as the anode.

The cathode is the electrode that undergoes reduction, receiving the electrons lost by the anode. In this case, the silver oxide (Ag₂O) electrode will receive electrons and will be reduced to silver (Ag), thus acting as the cathode. Summarizing, (a) Zinc electrode acts as the anode.

To answer part (b) of the question, we need to compare the energy densities of Li-ion, nickel-cadmium, and lead-acid batteries to the energy density of a silver oxide battery. The energy density is a measure of how much energy the battery can store per unit of mass or volume. Based on the general properties of these batteries, we can deduce the following energy densities: - Li-ion battery: High energy density; - Nickel-cadmium battery: Medium energy density; - Lead-acid battery: Low energy density. The energy density of a silver oxide battery is relatively high due to the high capacity of silver to store chemical energy. Considering that information, we can deduce that the Li-ion battery has an energy density most similar to the silver oxide battery.