A noble gas with a high power of fog penetration used in aerodrome beacons is?

Analysis

The question asks for a specific noble gas known for its ability to penetrate fog, making it ideal for use in airport (aerodrome) beacons and warning lights.

Concept Explanation

Noble gases (Group 18 elements) are known for being chemically inert. However, they have distinct applications based on their physical properties, particularly how they behave when an electric current is passed through them in a discharge tube.

• Neon (Ne): When electricity passes through neon gas, it emits a bright, intense reddish-orange light. This light has a long wavelength, which allows it to scatter less and penetrate through fog, mist, and rain much better than white light. This property makes it the standard choice for high-visibility signage and airport landing beacons.
• Argon (Ar): Often used in light bulbs to prevent the filament from burning out, but it does not have the same high-visibility penetration power as neon.
• Krypton (Kr): Used in high-speed photography flashes and some specialized lamps, but not primarily for fog penetration in beacons.
• Helium (He): Used in balloons and airships due to its low density, but it is not used for lighting beacons.

Step-by-Step Solution

1. Identify the requirement: We need a gas that produces a light capable of cutting through poor visibility conditions like fog.
2. Evaluate the options: • Argon, Krypton, and Helium do not possess the specific high-intensity, long-wavelength emission characteristic required for fog-penetrating beacons. • Neon produces a characteristic red-orange glow that is highly visible even in adverse weather conditions.
3. Conclusion: Because of its high visibility and ability to penetrate fog, neon is the gas used in aerodrome beacons.

Exam Tip

When you see questions about noble gases in JAMB, remember these common uses:

• Neon: Advertising signs and airport beacons (high visibility).
• Argon: Electric light bulbs (inert atmosphere).
• Helium: Weather balloons and airships (low density).
• Xenon: Strobe lights and high-intensity car headlights.