Why is the surface of sodium only shiny when it is freshly cut?
Answer (3)
Like most metals, sodium will oxidize when left exposed to air for an extended period of time, much like a rusted nail: it may have started shiny but over time it will rust as it is exposed to oxygen.
Sodium is highly reactive and tarnishes rapidly when exposed to air, forming a dull coating that obscures its shiny surface; in contrast, silver does not react as quickly with water and retains its luster. ;
Sodium appears shiny when freshly cut because its smooth surface reflects light well. However, upon exposure to air, it oxidizes quickly, forming sodium oxide, which is dull and loses that shiny luster. This oxidation process occurs almost immediately and causes the sodium to look less appealing over time.
;
