Science 5.2 Conduction
What Do You Already Know about Conduction?
Conduction is one of the three main ways that heat energy moves from place to place. Conduction is the process by which heat energy is transmitted through collisions between neighboring atoms or molecules.
How Does Heat Transfer from One Substance to Another through the Process of Conduction?
Conduction occurs whenever a substance increases in temperature because of direct collisions with particles of a warmer substance. An example of conduction is a metal pot on a stove burner. The burner under the metal transfers thermal energy to the pot. If the pot is a good conductor of heat, the sides and handle of the pot will also heat up.
How and why are good conductors and good insulators similar and different in how they transfer heat by conduction?
Conductors are materials that allow the flow of electric current, whereas insulators do not. While conductors and insulators are different in that respect, their similarity is in their makeup of atoms. It is these atoms that either have room to float around to facilitate conduction or have little freedom to move around; this lack of freedom makes the material they form an insulator.
How does heat travel by conduction ?
Heat travels by conduction as the energy of faster moving molecules in warm areas is transferred by direct contact to slower moving molecules in cooler areas. Heat travels through different materials at different rates. Heat travels through materials called conductors very quickly. Metals are good conductors. Heat travels through materials called insulators very slowly. Wood is an example of an insulator.
conduction
The direct transfer of heat from one substance to another substance that it is touching.
What is thermal equilibrium?
When a hot object is placed in contact with a cold object, heat energy travels from the hot object to the cold object until both objects are the same temperature.At some point, the fast-moving particles will have transferred so much of their energy to the slower particles that all of the particles will be moving at exactly the same speed!
How Does Heat Transfer from One Substance to Another through the Process of Conduction?
When a hot substance is introduced to a cool substance, the fast-moving particles collide with the slower moving ones. This causes them to move faster and increase in temperature. This is how heat conduction occurs between substances.
Thermal energy
always transfers from the higher temperature object to the lower, or colder, temperature object. It never happens the other way around!
Insulators
are the opposite of conductors—they restrict or resist the flow of heat. Insulators help keep substances at a constant temperature because they do not quickly absorb energy from the substance.
Examples of conductors
copper, aluminum, gold, silver, iron
In liquids
liquids do not conduct thermal energy as well as solids because the particles are not in as much contact with each other.
In gases
the particles are spaced far apart from each other, and they only interact with and transfer thermal energy to one another when they bump into each other. Liquids do not conduct thermal energy as well as solids because the particles are not as tightly packed together.
In solid materials
thermal energy is conducted quickly through a solid because the particles are tightly packed.
Examples of insulators
wood, glass, porcelain, rubber,water