Question

ordering question
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place the stages in the formation of an air mass in proper order, beginning with the first stage.
instructions
air over a large, warm surface is heated by conduction.
heated air rises because it is less dense than the surrounding air.
over days or weeks, the heated air takes on the characteristics of its source region.

Explanation:

The formation of an air mass starts with air being heated over a warm surface via conduction. The heated air then rises due to lower density than surrounding air. Over time, the air mass acquires characteristics of its source region.

Answer:

1. Air over a large, warm surface is heated by conduction.
2. Heated air rises because it is less dense than the surrounding air.
3. Over days or weeks, the heated air takes on the characteristics of its source region.