What gas is transported in a liquid state and has similar properties to argon?

The correct answer is helium because it is a noble gas that shares properties with argon, such as being inert and non-reactive under most conditions. Both helium and argon are used as shielding gases in welding processes, helping to protect the weld area from contamination with atmospheric gases.

Helium is often transported in a liquid state for various industrial applications, including arc welding, where its low density and thermal conductivity can be advantageous. In GTAW, helium can provide a hotter arc and is especially useful for welding materials that require higher heat input.

The other choices, while related to gases, do not serve the same purpose in welding as helium and argon do. Nitrogen, although used in some applications, can create issues due to its reactivity, while carbon dioxide is utilized in processes like MIG welding but is not similar to argon in behavior. Ozone is a form of oxygen and is not used as a shielding gas in welding, making helium the more suitable answer in this context.