Atmospheric gas is a term used to describe the gases present in the Earth's atmosphere. These gases include nitrogen, oxygen, carbon dioxide, methane, and others. Rather than using the term "atmospheric gas", there are several synonyms that can be utilized. "Air gas" is a less scientific term that can be used to describe the mixture of gases in the atmosphere. Another synonym is "ambient gas", as these gases are present in the surrounding environment. "Atmosphere gas" is another alternative, referring to gases that make up the Earth's atmosphere. Regardless of the synonym used, it is important to understand the significance of these gases in our environment.