Cesium, an extremely reactive alkali metal, must be stored with utmost care to prevent violent reactions and ensure safety. Here's how cesium is typically stored:

Mineral Oil Immersion: Cesium is usually stored submerged in a layer of mineral oil. The oil acts as a barrier, preventing contact with air and minimizing the risk of reactions with moisture or oxygen. The mineral oil also provides a protective layer, reducing the chances of explosions or fires.

Sealed Glass Ampoules: Cesium is sometimes stored in sealed glass ampoules under vacuum or an inert atmosphere (e.g., argon or nitrogen). These ampoules are then further enclosed in plastic or metal containers for additional protection and to prevent breakage.

Controlled Atmosphere: To prevent reactions with air, cesium can be stored in a controlled atmosphere, such as an argon-filled glovebox. Gloveboxes provide an oxygen-free environment and allow researchers to handle cesium without exposing it to air.

Specialized Containers: Specially designed containers, made from compatible materials (such as tantalum or stainless steel) and equipped with leak-tight seals, are used for storing cesium. These containers are resistant to corrosion and can withstand the high reactivity of cesium.

Low-Temperature Storage: Cesium is often stored at low temperatures, usually in a cryogenic environment, to minimize its reactivity and keep it in a more stable state.

Note that handling and storing cesium require specific expertise and safety precautions due to its hazardous nature. Only trained professionals with proper facilities should handle cesium, and stringent safety protocols must be followed to avoid accidents and injuries.