1. Which type of air is largest as it expands? Cold Air

Dry Air

Frigid Air

Warm Air

Warm Air is largest as it expands.

On heating, air tend expands and it's contracts when cooling.

When air is heated, it particles move away from each other which make them to occupy more space compared to cold air. The warm air is less dense compared the cold air or any type of air. The warm air, when heated rises up and the cold air remains at the down.

Therefore, Warm air expand most because it particles move away from each other and occupy space.

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a and c are the answeres