Industrial gases — applications of neon Considering common industrial and lighting applications, which of the following statements about neon gas is correct?
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AIt is flammable in nature
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BIt is used in color discharge tubes (neon signs)
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CIt is commonly filled in lamps with tungsten filaments
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DAll (a), (b) and (c)
Answer
Correct Answer: It is used in color discharge tubes (neon signs)
Explanation
Introduction / Context:Neon is a noble (inert) gas widely recognized for its bright reddish-orange glow in electrical discharge tubes, popularly called “neon signs.” Understanding its properties clarifies where it is and is not used.
Given Data / Assumptions:
- Chemical nature: inert, non-flammable.
- Lighting applications differ between discharge tubes and incandescent lamps.
Concept / Approach:In discharge lighting, an electric field excites neon atoms, which emit characteristic light. In incandescent lamps with tungsten filaments, argon or nitrogen (and in some cases krypton/xenon) are typical fills to reduce filament evaporation; neon is not standard for these.
Step-by-Step Solution:Check flammability: neon is inert → not flammable → option (a) false.Check discharge use: neon is widely used in luminous tubes → option (b) true.Check filament lamps: neon is not the common fill → option (c) false.Therefore, only (b) is correct.
Verification / Alternative check:Lighting references list argon/nitrogen blends in incandescent bulbs and neon for discharge signage.
Why Other Options Are Wrong:
- (a) Conflicts with neon’s noble gas inertness.
- (c) Typical incandescent fills are not neon; neon would cause different behavior and coloration.
- (d) Groups incorrect statements with the correct one.
Common Pitfalls:
- Assuming all noble gases are interchangeable across lamp types.
Final Answer:It is used in color discharge tubes (neon signs)