Final answer:
The term for the part of the total atmosphere attributable to the water vapor content is the hydrosphere, which includes all water on Earth's surface and in the atmosphere.
Step-by-step explanation:
The part of the total atmosphere attributable to the water vapor content is called the hydrosphere. Earth's atmosphere consists of five layers: the troposphere, the stratosphere, the mesosphere, the thermosphere, and the exosphere. The troposphere is the lowest layer and contains the most water vapor, making it primarily responsible for weather events and climate conditions that support life. However, the term hydrosphere specifically refers to all the water on Earth's surface, including the water vapor in the atmosphere, so it encompasses more than just the atmospheric water vapor found in the troposphere.