When plasma and gas are mixed together, the plasma and gas can interact in a number of ways. The plasma can transfer energy to the gas, which can cause physical and chemical changes in the gas. For example, the plasma can ionize the gas molecules, which can lead to the creation of new chemical compounds. Additionally, the plasma can heat up the gas, which can cause it to expand and create a shock wave. In some cases, the interaction of plasma and gas can lead to the creation of a plasma-gas hybrid state, which can have unique properties and behaviors.