Answer:
Here are the atmospheric gases matched with their formation processes:
1. Oxygen - Released into the atmosphere as a product of photosynthesis by plants and phytoplankton.
2. Carbon dioxide - Added to the atmosphere primarily through the combustion of fossil fuels, deforestation, and various human activities.
3. Water - Evaporates from Earth's surface and is added to the atmosphere as water vapor through the process of evaporation and transpiration from plants.