why does hot air rise while cold air sinks?\n○ hot air is less dense than cold air\n○ cold air is less dense…

why does hot air rise while cold air sinks?\n○ hot air is less dense than cold air\n○ cold air is less dense than hot air\n○ the particles in hot air are close together\n○ hot air has more mass than cold air

why does hot air rise while cold air sinks?\n○ hot air is less dense than cold air\n○ cold air is less dense than hot air\n○ the particles in hot air are close together\n○ hot air has more mass than cold air

Answer

Brief Explanations:

To determine why hot air rises and cold air sinks, we analyze the density concept. When air is heated, its particles gain energy and move apart, increasing volume. Since density is mass per unit volume ($\rho = \frac{m}{V}$), for the same mass, a larger volume means lower density. Hot air has lower density than cold air (cold air particles are closer, so higher density for the same volume). The other options are incorrect: cold air is more dense (so second option is wrong), hot air particles are spread out (third option is wrong), and hot air doesn't have more mass (fourth option is wrong).

Answer:

A. hot air is less dense than cold air