Nitrogen is used to keep food frozen during transportation. Which properties make it suitable for this?

Gaseous nitrogen has unique chemical and physical properties that make it suitable for use in food processing. Nitrogen is inert which means it will not react with prepared food materials, which can alter their aromas or flavors. Also, gaseous nitrogen will effectively displace oxygen minimizing oxidation and the growth of microorganisms that cause foods to lose their freshness and deteriorate faster.

Explanation:

Source: https://www.generon.com/using-nitrogen-gas-in-food-packaging/

the answer is minerals.

because natural gas is colorless, odorless, and tasteless, distributors add mercaptan (a chemical that smells like sulfur) to give natural gas a distinct unpleasant odor (it smells like rotten eggs). they locate the types of rock that are likely to contain natural gas deposits.