Final answer:
Cesium is stored in argon gas to prevent its violent reaction with water or air due to argon's chemical inertness and stability. Argon protects reactive alkali metals like cesium by providing an environment that does not initiate any unwanted reactions.
Step-by-step explanation:
Samples of the alkali metal cesium are usually stored in argon gas because cesium is highly reactive with air and water. Alkali metals, such as cesium, can react violently with humidity in the air or any moisture to produce hydrogen gas and heat, often igniting and causing an explosion. On the other hand, argon is a noble gas, which is characterized by a filled outer electron shell, making it chemically inert. The inertness of argon means it does not react with the cesium, thus providing a protective atmosphere that prevents cesium from reacting with other elements or compounds it would normally react with in the air.
Argon's use in situations that require chemical inertness can also be found in other applications. For example, it is also utilized in the manufacturing process of gas-filled electric light bulbs due to its lower heat conductivity and ability to inhibit the vaporization of the tungsten filament, thereby prolonging the bulb's life. The stability and lack of reactivity of argon make it an ideal choice for storing reactive elements like cesium.