In Earth science, the concentration of water vapour in the troposphere generally varies in which approximate range by volume?

Introduction / Context:
The troposphere is the lowest layer of the atmosphere where most weather phenomena occur. Water vapour content in this layer is highly variable and plays a key role in cloud formation, precipitation and heat balance. General science exams often test your understanding of the typical range of water vapour concentration in the troposphere, because it highlights how small changes in composition can significantly affect climate and weather patterns.

Given Data / Assumptions:

• The question asks for the approximate range of water vapour concentration in the troposphere.
• Options include 0 to 4 percent, 10 to 14 percent, 20 to 24 percent and 30 to 34 percent.
• We assume the values are by volume or by mixing ratio at typical atmospheric conditions.

Concept / Approach:
In standard atmospheric science, the concentration of water vapour in the troposphere varies greatly with location, altitude and temperature. Near the surface in warm, humid regions it can approach several percent, while in cold or high altitude regions it can be almost zero. Typical textbooks state that water vapour ranges from nearly 0 percent up to about 4 percent by volume in the troposphere. Higher percentages such as 10 percent or more are not realistic for average atmospheric composition, because nitrogen and oxygen remain the dominant gases.

Step-by-Step Solution:
Step 1: Recall from school geography that water vapour is a variable component of the atmosphere. Step 2: Remember that its concentration is usually expressed as up to about 4 percent by volume in very humid air. Step 3: Compare this remembered range with the options provided. Step 4: Option 0 to 4 percent matches the standard statement that water vapour varies from nearly zero in cold, dry air to a few percent in warm, moist air. Step 5: The other ranges like 10 to 14 percent or higher would make water vapour a major portion of the atmosphere, which is not true. Step 6: Therefore, 0 to 4 percent is the only scientifically reasonable option.

Verification / Alternative check:
You can verify this by remembering the composition pie charts of the atmosphere. Such charts show nitrogen and oxygen making up almost all of the air, with argon and other gases taking a small share. Water vapour is always shown as a small, variable wedge that may reach up to 4 percent in extreme tropical humidity. No chart shows water vapour as ten or twenty percent of atmospheric gases, confirming that higher ranges in the options are unrealistic.

Why Other Options Are Wrong:
10 to 14 percent: This would imply that more than one tenth of the atmosphere is water vapour, which is far beyond observed values and does not match basic atmospheric composition data.
20 to 24 percent: Such a high fraction of water vapour is not compatible with the dominance of nitrogen and oxygen in the air and is not supported by any standard reference.
30 to 34 percent: This would mean roughly one third of the atmosphere is water vapour, which is clearly impossible under natural Earth conditions.

Common Pitfalls:
A common error is to overestimate water vapour content because we strongly associate the troposphere with clouds and moisture. Students sometimes think that because humid air feels heavy or sticky, it must contain a very large fraction of water vapour. In reality, even a few percent is enough to make a big difference. Always rely on the approximate scientific range of 0 to about 4 percent to avoid such exaggerations.

Final Answer:
The concentration of water vapour in the troposphere generally varies in the range of 0 to 4 percent by volume.