Which is not a characteristic of Argon?

• A. Inert shielding gas
• B. Non-reactive
• C. Low thermal conductivity
• D. Excellent thermal conductor

Answer: (D)

Argon is a noble gas used as a shielding gas in welding because it is inert and non-reactive. That inertness means it doesn’t readily react with the molten metal, protecting the weld pool from oxidation and contamination. It also has low thermal conductivity, so it doesn’t transfer heat away from the weld area quickly, helping to maintain arc stability and protect surrounding metal.

Therefore, the statement that Argon is an excellent thermal conductor is not a characteristic of Argon. Its low thermal conductivity is the correct trait, not high conductivity. The other properties described—being inert and non-reactive—fit Argon well.