Hot air rises because when a substance is hot, its molecules are farther apart, which makes the hot air less dense and, therefore, lighter than cooler air. Air is generally warmer nearer the surface of the Earth because of the sun's radiating heat. When hot air rises, it starts to get cooler and eventually it sinks back down to the surface.Know More
Heat itself does not rise, but hot air does. The cycle of rising hot air and cool sinking air is what creates many weather phenomenon, such as tornadoes and hurricanes as well as everyday thunderstorms and breezes. With global warming, the warmer seas and ground will cause this cycle to become exacerbated. There is a good chance that in the future, stronger winds, thunderstorms, tornadoes and hurricanes will become stronger and more frequent.
When the hot air rises, it creates thermals which are pockets rising upward. During the mornings, these thermals do not rise very high before cooling as the air is cooler after a night without radiating heat. Later in the day, the air near the ground gets warmer throughout the day and if the thermal rises high enough, some of the water vapor in the thermal builds up and forms into a cloud.Learn more about Thermodynamics
Hot-air balloons work based on the principle that hot air is lighter than cool air. By using a propane burner that heats the air inside the balloon, the air inside the envelope, or the top part of the balloon, becomes lighter than the surrounding air, causing the balloon to rise.Full Answer >
Hot air rises and cold air falls because cold air molecules are densely packed together, making them heavier, and hot air molecules have more space between them, making them warm enough to rise. It is for this reason that hot air balloons move upwards. In addition to temperature affecting air density, humidity plays a role.Full Answer >
Air is a good insulator because its molecules are very far apart. This makes it difficult to transfer heat, according to Dr. Ken Mellendorf, a physics professor at Illinois Central College.Full Answer >
Water has a high boiling point because its molecules are bound together by hydrogen bonding, which is a very strong intermolecular force. It takes more kinetic energy, or a higher temperature, to break the hydrogen bonding between water molecules, thus allowing them to escape as steam.Full Answer >