Which gas is colorless, odorless, and tasteless, and is used for shielding in welding?

The gas used for shielding in welding that is colorless, odorless, and tasteless is argon. This inert gas is ideal for the Gas Metal Arc Welding (GMAW) process because it does not react with the molten metal during welding, which helps to protect the weld pool from contamination by atmospheric gases, such as oxygen and nitrogen. The use of argon enhances the quality of the weld, providing a stable arc and minimizing oxidation, which can lead to defects in the weld.

Argon's properties make it particularly beneficial for welding processed metals like aluminum and stainless steel, where maintaining the integrity of the weld is crucial. It can also effectively provide the necessary shielding in high-quality applications because it remains stable under the high temperatures encountered in the welding process, ensuring clean and strong welds.