Convection transports heat over a greater distance than conduction. However, conduction must eventually transport heat from the gas to the other item by molecular contact. Thus, conduction is slower than convection.
Convection is a quicker process than conduction. This is due to the fact that in the case of convection, which occurs largely in fluids, molecules have the freedom to move and vibrate from their positions at a higher rate, but in conduction, molecules do not have as much room to move and vibrate.
Conduction: The transfer of heat through solid objects by means of molecular motion. In other words, it's the slowest way of transferring heat because only one molecule at a time can change position, while waves propagate through liquids and gases as wave packets.
Convection: The bulk movement of a fluid caused by the difference in temperature between two sides of the fluid. This causes heat to be transferred more quickly because there are more molecules moving per unit area. Even though convection is a faster method of heat transfer, conduction is still important in situations where geometry limits the flow of heat.
Here are some examples of how conduction and convection affect heat transfer:
If you put your hand on an oven burner for too long, you'll experience heat pain due to the existence of thermal conductivity. This means that even though the burner element is hot, the rest of the object is not yet heated because heat cannot be transmitted through solids.
The same thing happens with a cold liquid metal ball dropped into a bucket of water.
Conduction, convection, and radiation all transport heat. Conduction is heat transmission by direct contact, such as when frying an egg. Convection heat transfer is achieved by the flow of gases or liquids, as in most home furnaces, laundry dryers, and automobile warmers. Radiation is the emission of energy waves, such as from the sun or a hot stove. It is used to cook food at high temperatures.
Eggs are cooked by both conduction and convection. When cooking eggs by conduction, you must provide a solid surface upon which the heat can conduct into the egg. This will ensure that the yolk does not overcook before the white has set. For this reason, it is important not to use a metal bowl when frying eggs because they will retain their temperature more quickly than a ceramic or glass bowl.
When frying eggs, it is best to use a deep-fat fryer so the oil is not contacting the bowl itself. This prevents the bowl from becoming too hot and breaking when removing the egg. It also ensures that no other foods are fried in the oil with your eggs. Be sure to follow the manufacturer's instructions for proper maintenance and care of your fryer.
Eggs should be served immediately after they are done cooking to preserve their nutrients.
Heat flows from areas of higher heat to areas of lower heat by direct contact in conduction. Warmer molecules vibrate quickly and clash with other molecules nearby, exchanging energy. Heat emitted from the ground causes convection cells to form in the atmosphere. These are regions of rising warm air and falling cold air that carry heat away from Earth's surface into space.
Conduction also causes temperature differences between objects that touch each other but do not physically contact. For example, if you were to put your hand on a hot stove top or a radiator, you would feel its heat because both objects are conducting warmth from their respective surfaces.
Atoms in the atmosphere that have lost electrons become positively charged and want to return to being neutral. They do this by jumping from atom to atom through other atoms, which carries the charge. This is why touching two wires of different signs charges will spread out through both wires - positive particles jump from wire to wire until they find another wire with an equal number of negative particles. This is how the atoms in your body stay cool despite exposure to extreme heat; electricity cannot flow through a dead body. The atoms in objects like stoves and radiators do not go completely cold because they still have some residual heat left over from when they last had atoms jump them.