Understanding Noble Gas Uses

Noble gases are a group of chemical elements that have similar properties; under standard conditions, they are all odorless, colorless, monatomic gases with very low chemical reactivity. Despite their inertness, they have various practical applications, particularly in different types of lighting because they glow when an electric current passes through them, and their inert nature prevents reactions with filament materials.

The question asks us to match specific noble gases with their common uses. Let's analyze the given lists and determine the correct pairings.

List I (Noble gas):

• A. Argon
• B. Neon
• C. Krypton
• D. Xenon

List II (Use):

• 1. In lights for advertising display
• 2. Airport landing lights and in light houses
• 3. Light in photographer’s flash gun
• 4. In tungsten filament to last

Now let's match the noble gases with their appropriate uses based on scientific properties and common applications:

• Argon: Argon is widely used in incandescent light bulbs. It is an inert gas, and filling the bulb with argon (or a mixture of argon and nitrogen) at a certain pressure reduces the rate of evaporation of the hot tungsten filament. This prevents the filament from becoming thin and breaking prematurely, thus extending the bulb's lifespan. This matches use 4.
• Neon: Neon gas is famously used in "neon signs" for advertising displays. When an electric discharge passes through neon gas at low pressure, it emits a bright reddish-orange light. Different colors are achieved by mixing neon with other gases or using phosphor coatings, but pure neon provides the iconic red. This matches use 1.
• Krypton: Krypton, like argon, is used in some higher-quality incandescent bulbs and also in fluorescent lamps. It produces a brighter and whiter light than argon for the same power input. Krypton's properties make it suitable for specialized high-intensity lighting, including some types of airport runway lights and lighthouses where a reliable and bright light source is needed. This matches use 2.
• Xenon: Xenon produces a very bright, intense white flash of light when a high-voltage pulse is discharged through it. This makes it ideal for applications requiring short, powerful bursts of light, such as in photographic flash lamps (like in a photographer's flash gun) and strobe lights. It is also used in high-intensity discharge (HID) lamps for applications like car headlights and cinema projectors. This matches use 3.

Based on these matches, we can form the pairs:

A goes with 4 (Argon - In tungsten filament to last)

B goes with 1 (Neon - In lights for advertising display)

C goes with 2 (Krypton - Airport landing lights and in light houses)

D goes with 3 (Xenon - Light in photographer’s flash gun)

Let's represent the matching pairs in a table:

The correct combination of pairs is A-4, B-1, C-2, D-3. We should look for this sequence in the given options.

Revision Table: Noble Gas Applications

Additional Information on Noble Gas Uses

Noble gases are group 18 elements (also known as Group VIIIA or 0) in the periodic table. Their full valence electron shells make them very stable and unreactive under most conditions. This inertness is key to many of their uses, especially in creating protective atmospheres.

• Lighting: Their ability to emit light when an electric current is passed through them is utilized in various types of lamps, from simple advertising signs to high-intensity discharge lamps and specialized photographic flashes.
• Creating Inert Atmospheres: Argon is widely used as an inert shielding gas in welding (like TIG welding) to protect the weld area from atmospheric gases like oxygen and nitrogen, which could cause defects.
• Cryogenics: Helium has the lowest boiling point of all elements, making it essential for cooling superconducting magnets in MRI machines and particle accelerators like the Large Hadron Collider.
• Medical Applications: Xenon can be used as an anesthetic. Helium is sometimes mixed with oxygen for patients with severe asthma or other breathing difficulties because the lighter mixture is easier to inhale. Radon, being radioactive, has been used historically in radiotherapy, though its use has decreased.
• Other Uses: Neon is used in voltage detectors. Krypton and Xenon are used in some types of lasers.

The specific light color emitted by a noble gas discharge depends on the gas itself and the pressure. For example, neon is reddish-orange, helium is yellowish-white, argon is blueish-purple, krypton is greenish-white, and xenon is blueish-white.