Heat and temperature space a very closely related topic, and as such, the difference in between the two deserve to be a little confusing. The core difference is the heat deals with thermal energy, whereas temperature is more concerned with molecular kinetic energy.

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Whats the difference?

Heat defines the transport of heat energy between molecules within a system and is measure in Joules.<2> heat measures how power moves or flows. An item can obtain heat or shed heat, yet it cannot have heat. Heat is a measure up of change, never ever a building possessed by an object or system. Therefore, it is classified together a procedure variable.

Temperature describes the typical kinetic energy of molecules within a product or system and also is measure in Celsius (°C), Kelvin(K), Fahrenheit (°F), or Rankine (R). That is a measurable physical property of an object—also recognized as a state variable. Other measurable physics properties encompass velocity, mass, and density, to surname a few.<3>


Heat is a transfer of thermal energy caused through a difference in temperature in between molecules.


Thermal power can be otherwise construed as the full microscopic kinetic and also potential energy of a system.

Second law of Thermodynamics

The second law of thermodynamics is a complicated topic that requires extensive study in the ar of thermodynamics to important understand. However, because that the purpose of this article, only one tiny aspect demands to it is in understood and that is the reality that heat will always flow spontaneously indigenous hotter substances to chillier ones. This simple statement defines why an ice cream cube doesn"t kind outside top top a hot day or why that melts once dropped in a bowl of warmth water.

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Thought experiment

Imagine the aforementioned ice cube dropped into a bowl of heat water—the ice must get heat (thermal energy) from the water in the bowl (see preceding paragraph). Adding thermal energy leads to boost in the kinetic energy of the ice molecule, and thus rise in temperature. This is known due to the fact that temperature is in fact the measure of the median kinetic power of the molecules. Furthermore, the ice cream will continue to get thermal power causing its molecule to relocate faster and also eventually break their intermolecular bonds or melt.

In conclusion, the transfer of warmth or thermal energy will typically readjust the temperature the the substance, but no always! because that example, in ~ the minute when the ice in the bowl transforms to water those water molecules will certainly be at the precise same temperature as once they to be ice. In this case, rather of the thermal energy doing work to rise the kinetic energy, it does occupational to break the intermolecular bonds, leading to a readjust of state. However, as time walk on the temperature of the freshly melted ice cream will rise until every little thing within the key reaches equilibrium—meaning a continuous temperature throughout.