Question

Identify use of argon from following.

• A. In supersonic wind tunnels
• B. For magnetic resonance imaging
• C. For producing inert atmosphere in welding
• D. For production of lasers

Hint:

Remember that Argon's primary commercial value lies in its chemical "laziness" (inertness) combined with its high abundance in air (around 0.93%), making it the default economic option whenever a process requires an unreactive gas blanket.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
The question requires us to identify a correct, standard industrial application of the noble gas Argon (Ar) from the provided options.

Step 2: Key Formula or Approach:
Argon is a Group 18 element (noble gas) that is chemically inert and relatively inexpensive to isolate compared to other noble gases, making it an excellent choice for applications that require an oxygen-free environment.

Step 3: Detailed Explanation:
Let's evaluate the chemical functions of each option:

In supersonic wind tunnels: Helium or specialized compressed gas mixes are preferred here due to gas dynamic properties.

For magnetic resonance imaging (MRI): Liquid Helium is used exclusively to cool down the superconducting electromagnets to extremely low temperatures ($4.2\ \text{K}$).

For producing inert atmosphere in welding: This is the principal industrial application of Argon. In Gas Tungsten Arc Welding (TIG) and Gas Metal Arc Welding (MIG), argon acts as a shielding gas to prevent hot metal from reacting with oxygen and nitrogen in the air.

For production of lasers: While Argon-ion lasers exist, it is not its primary commercial or textbook descriptor compared to the shielding gas application.

Step 4: Final Answer:
Argon is widely used for producing an inert atmosphere in metallurgical welding, matching option (C).