Why are noble gases non-flammable?

Noble gases are non-flammable because they have a full valence electron shell, making them chemically inert and unreactive.

Noble gases, which include helium, neon, argon, krypton, xenon, and radon, are located in Group 18 of the periodic table. They are characterised by their full valence electron shells, which means they have the maximum number of electrons in their outermost energy level. This full shell gives them a stable electron configuration, making them chemically unreactive or inert.

Flammability is a chemical property that describes a substance's ability to ignite or burn, which involves a chemical reaction with oxygen. This reaction, known as combustion, requires a substance to have a certain reactivity level. Since noble gases are chemically inert due to their full valence shells, they do not readily engage in chemical reactions, including combustion. Therefore, they are considered non-flammable.

In addition, noble gases have low boiling points and are generally in the gaseous state at room temperature. Despite being gases, their unreactivity prevents them from combining with oxygen to ignite or burn. This is in contrast to other gases like hydrogen or methane, which are highly flammable due to their reactivity with oxygen.

In summary, the non-flammability of noble gases is a result of their stable electron configuration, which makes them chemically inert and unreactive. This prevents them from undergoing combustion reactions, making them non-flammable.