Heart pacemakers are often powered by lithium-silver chromate “button” batteries. The overall cell reaction is:

2Li(s) + Ag2CrO4(s) --------> Li2CrO4(s) + 2Ag(s)
Lithium metal is the reactant at one of the electrodes of the battery. Is it the anode or the cathode?

In this cell reaction, lithium metal (Li) is consumed during the reaction, indicating that it serves as the anode. The electrode at which oxidation occurs is called the anode, while the electrode at which reduction occurs is called the cathode.

To determine whether lithium metal is the anode or cathode in the cell reaction, we need to understand the definitions of the anode and cathode.

In an electrochemical cell, the anode is the electrode where oxidation occurs. Oxidation involves the loss of electrons, and it is known as the negative electrode. On the other hand, the cathode is the electrode where reduction occurs. Reduction involves the gain of electrons, and it is known as the positive electrode.

Looking at the given cell reaction:
2Li(s) + Ag2CrO4(s) → Li2CrO4(s) + 2Ag(s)

In this reaction, the lithium metal (Li) is being oxidized from its elemental state (Li) to form Li2CrO4. Oxidation means losing electrons, so the anode is where lithium metal is present.

Therefore, lithium metal is the anode in this cell reaction.

The Li==> Li^+ + e is the anode. That is the one losing electrons.