Why does heated air rise?

Answer 1

Substances that have internal movement(gas, liquid, and solids to a certain degree) will have convection currents. The concept is most easily understood in a gas. As gases are heated their molecules travels faster and faster. The faster they move and the more the kinetic energy involved in the collisions causes the gas to increase in volume. This means that the particles are further apart and therefore the density of the gas decreases. And substances with lower density will rise. This can also be thought of as kinetic and potential energies. As the gas is heated the molecules inside have increased kinetic energy. The increased energy of the molecules allows the molecule to reach higher potential energy levels(which means the molecule can rise).

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Answer 2

As the air is heated the molecules become excited and they move further apart expanding the air. Expanded air is less dense so it floats on top of the cold air.

Substances that have internal movement(gas, liquid, and solids to a certain degree) will have convection currents. The concept is most easily understood in a gas. As gases are heated their molecules travels faster and faster. The faster they move and the more the kinetic energy involved in the collisions causes the gas to increase in volume. This means that the particles are further apart and therefore the density of the gas decreases. And substances with lower density will rise. This can also be thought of as kinetic and potential energies. As the gas is heated the molecules inside have increased kinetic energy. The increased energy of the molecules allows the molecule to reach higher potential energy levels(which means the molecule can rise).

Answer 3

For the same reason that objects float in water. In general, objects that are less dense tend to float if placed in a more dense medium. Hot air is less dense than cold air, so it will move upwards.

Answer 4

As the air is heated the molecules become more bouncy or excited and they move further apart expanding the air. And in turn expanded air is less dense so it floats on top of the cold air.

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The above is correct but I have a different way of looking at it.

Heat is actually the vibration of the components of stuff (the smallest bits that stuff is made of called molecules or atoms). When you increase heat think of it as making the molecules vibrate a bigger amount - like waving your hand - when you say a little good bye you wave your hand just a little bit but when you say a big good bye you wave your whole arm.

Waving you whole arm takes up more space than just a little wave and in the same way when things are hotter the stuff they are made of takes up more space, they expand!

When stuff expands and takes up more space, there is less stuff in a volume of that space than when it was cool, so hot stuff is lighter than cool stuff. Being lighter it floats up - so hot air rises.

Answer 5

Air rises when heated because the molecules are moving faster than they were before they were heated. When molecules move faster they move with higher force pushing themselves upward and outward.

Answer 6

The short answer is that warm air is less dense [lighter] than cooler air, and therefore being less dense, rises through cooler/denser air until it reaches a level of equal density where it then "floats." A longer answer is that except at a temperature of Absolute Zero, all molecules are in random movement, constantly bumping into and bouncing off of each other. As a result, in a gas such as air, there is space between the molecules and as the temperature increases, the movement and collisions become more violent causing the molecules to move further apart [expand] therefore, creating more space. If unconfined, this expansion means that there are fewer molecules in a given same space than were there at lower temperatures. That means that as the unconfined gas, air in the context of this question, becomes lighter it wants to "float" [rise] to the top of the cooler air above and around it.

Answer 7

they spread out because they are moving and float above the cooler air

Answer 8

they spread out because they are moving and float above the cooler air

Answer 9

hot air rises because it is less dense than cold air