Incandescent Lamp Filling Gas

An incandescent lamp produces light by heating a filament until it glows. To ensure the filament lasts longer and functions correctly, the bulb is filled with a specific type of gas.

Reasoning for Gas Choice

• Oxidation Prevention: The filament (usually tungsten) is very hot and would quickly burn or oxidize if exposed to reactive gases like oxygen.
• Inert Atmosphere: To prevent oxidation and filament evaporation, the bulb is typically filled with an inert gas or kept under vacuum.
• Inert Gas Properties: Inert gases do not react chemically with the filament. Common choices include noble gases.

Analyzing the Options

• Argon Gas: Argon is a noble (inert) gas. Filling the bulb with argon helps prevent the filament from burning up and slows down its evaporation, extending the lamp's life. This aligns with the function of incandescent lamps.
• Oxygen Gas: Oxygen is highly reactive and would cause the filament to burn out almost instantly.
• Carbon Dioxide: While less reactive than oxygen, it can still react at high temperatures and is not the preferred choice for preventing filament degradation.
• Sulphur Oxide: These are reactive gases and unsuitable for filling incandescent bulbs.

Conclusion

Based on the need for an inert atmosphere to protect the filament, argon gas is the correct choice for filling an incandescent lamp.