Which of the following is the most commonly used inert gas in laboratory and industrial applications?

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

Answer: (D)

Verified step by step guidance

1. Understand that inert gases, also known as noble gases, are elements in Group 18 of the periodic table characterized by their lack of chemical reactivity under most conditions.
2. Recognize the common inert gases listed: Helium, Neon, Krypton, and Argon, each with different properties and typical uses.
3. Consider the abundance and cost-effectiveness of these gases; Argon is more abundant in the Earth's atmosphere compared to Krypton and Neon, making it more economical for widespread use.
4. Note that Argon is chemically inert and has physical properties (such as density and thermal conductivity) that make it suitable for creating inert atmospheres in welding, laboratory experiments, and industrial processes.
5. Conclude that due to its availability, cost, and inertness, Argon is the most commonly used inert gas in laboratory and industrial applications.