Question

why is rain likely when warm, moisture - laden air meets cold air?
a the lighter warm air will rise and cool down, causing condensation and rain.
b the cold air moves faster and pushes the warm air away, causing condensation and rain.
c the moisture in the warm air condenses on contact with the cold air, causing rain to fall.
d the cold air mixes with the warm air, reducing its temperature causing moisture to condense

Explanation:

When warm, moisture - laden air meets cold air, the warm air (which is less dense) rises. As it rises, it cools. When air cools, its capacity to hold moisture (water vapor) decreases. This causes the water vapor in the warm air to condense (change from gas to liquid). The condensed water droplets then form clouds and eventually fall as rain.

• Option A: This option correctly describes the process. The warm air rises (because it is less dense), cools, and condensation occurs leading to rain.
• Option B: Cold air does not "push the warm air away" in a way that directly causes condensation for rain in the described scenario. Cold air is denser and usually undercuts warm air, but the key is the rising and cooling of warm air.
• Option C: The moisture in the warm air does not condense just on "contact" with cold air. The warm air needs to rise and cool (adiabatic cooling) for significant condensation to occur.
• Option D: While mixing can occur, the main process is the rising of warm air (due to density differences) and its subsequent cooling, not just general mixing.

Answer:

A. The lighter warm air will rise and cool down, causing condensation and rain.