Final answer:
The least reactive metal, often termed an inert metal, is one that has the lowest tendency to be oxidized. Silver is an example of such a metal because it does not react violently with water and can be used to create things like drinking vessels, indicating its low reactivity.
Step-by-step explanation:
To determine which metal is the least reactive, we refer to the activity series of metals, which ranks metals from most to least reactive. The least reactive metals are referred to as inert metals. They are placed at the bottom of the activity series as they have the lowest tendency to be oxidized. Examples of inert metals include gold, silver, and platinum. These metals do not easily lose electrons and form positive ions, which is why they do not readily react with substances such as water or oxygen, a process called oxidation. In fact, the oxidation involves the loss of electrons, and inert metals have a very low reactivity due to their high resistance to losing electrons.
Considering the provided information, we can infer that silver is an example of such a least reactive metal, as opposed to sodium, which is highly reactive with water. As shown in the pictures comparing these two metals, silver does not react violently with water and remains unreactive, which allows it to be used to create utensils.