During high-temperature gas tungsten arc welding (GTAW) of titanium components, argon is highly preferred over nitrogen as a shielding gas to protect the weld pool. Which statement best explains this preference based on the chemical and physical properties of these elements?
Argon is less dense than nitrogen, allowing it to rapidly rise and disperse potential atmospheric contaminants away from the weld zone.
Argon is completely inert due to its stable monatomic electron configuration, whereas nitrogen can react with hot titanium to form brittle titanium nitride (TiNTiNTiN).
Argon is a diatomic element with a high bond enthalpy, absorbing excess heat from the arc to prevent the titanium from melting too quickly.
Argon reacts reversibly with titanium to form a temporary protective liquid compound on the surface that vaporizes as the weld cools.
48 exam-style questions on OCR GCSE Chemistry Properties of materials. Each one has a worked solution and a mark scheme showing where the marks go.