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Formally they have the same units. J/KPractically they don't, because (for heat capacity) you almost always add an amount soJ/K mol or J/K KgBut for entropy, the "unit" is often "per molecule/ atom " Those entities are countable, and a number is dimensionless.
Entropy is an extensive quantity.This means that the total entropy of a system is directly proportional to its size or mass. In other words, if you double the size of a system, you double its entropy. This is in contrast to intensive properties, which do not depend on the size of the system.Here's a simple example: * Imagine two identical boxes of gas. Each box has the same temperature, pressure, and volume. * Now combine the two boxes. The resulting system has double the volume, double the mass, and double the entropy.This extensive property of entropy is a fundamental principle in thermodynamics. It reflects the idea that larger systems have more ways to distribute energy and matter among their constituent particles, leading to a higher degree of disorder.
Entropy change (ΔS) is related to heat (Q) and temperature (T) by the equation: ΔS = Q / T
https://en.wikipedia.org/wiki/Second_law_of_thermodynamics#IntroductionHeat flowing from hot water to cold water
Temperature is a physical quantity that quantitatively expresses the attribute of hotness or coldness. Temperature is measured with a thermometer. It reflects the average kinetic energy of the vibrating and colliding atoms making up a substance.https://en.m.wikipedia.org/wiki/Temperature
Thermodynamic temperature is a quantity defined in thermodynamics as distinct from kinetic theory or statistical mechanics.Historically, thermodynamic temperature was defined by Lord Kelvin in terms of a macroscopic relation between thermodynamic work and heat transfer as defined in thermodynamics, but the kelvin was redefined by international agreement in 2019 in terms of phenomena that are now understood as manifestations of the kinetic energy of free motion of microscopic particles such as atoms, molecules, and electrons. From the thermodynamic viewpoint, for historical reasons, because of how it is defined and measured, this microscopic kinetic definition is regarded as an "empirical" temperature. It was adopted because in practice it can generally be measured more precisely than can Kelvin's thermodynamic temperature.This simulation illustrates an argon atom as it would appear through a 400-power optical microscope featuring a reticle graduated with 50-micron (0.05 mm) tick marks. This atom is moving with a velocity of 14.43 microns per second, which gives the atom a kinetic temperature of one-trillionth of a kelvin. The atom requires 13.9 seconds to travel 200 microns (0.2 mm). Though the atom is being invisibly jostled due to zero-point energy, its translational motion seen here comprises all its kinetic energy.Strictly speaking, the temperature of a system is well-defined only if it is at thermal equilibrium. From a microscopic viewpoint, a material is at thermal equilibrium if the quantity of heat between its individual particles cancel out. There are many possible scales of temperature, derived from a variety of observations of physical phenomena.Loosely stated, temperature differences dictate the direction of heat between two systems such that their combined energy is maximally distributed among their lowest possible states. We call this distribution "entropy". https://en.m.wikipedia.org/wiki/Thermodynamic_temperature
Two physical systems are in thermal equilibrium if there is no net flow of thermal energy between them when they are connected by a path permeable to heat. Thermal equilibrium obeys the zeroth law of thermodynamics. A system is said to be in thermal equilibrium with itself if the temperature within the system is spatially uniform and temporally constant.Systems in thermodynamic equilibrium are always in thermal equilibrium, but the converse is not always true. If the connection between the systems allows transfer of energy as 'change in internal energy' but does not allow transfer of matter or transfer of energy as work, the two systems may reach thermal equilibrium without reaching thermodynamic equilibrium.https://en.m.wikipedia.org/wiki/Thermal_equilibrium
"There is an important distinction between thermal and thermodynamic equilibrium. According to M?nster (1970), in states of thermodynamic equilibrium, the state variables of a system do not change at a measurable rate. Moreover, "The proviso 'at a measurable rate' implies that we can consider an equilibrium only with respect to specified processes and defined experimental conditions." Also, a state of thermodynamic equilibrium can be described by fewer macroscopic variables than any other state of a given body of matter. A single isolated body can start in a state which is not one of thermodynamic equilibrium, and can change till thermodynamic equilibrium is reached. Thermal equilibrium is a relation between two bodies or closed systems, in which transfers are allowed only of energy and take place through a partition permeable to heat, and in which the transfers have proceeded till the states of the bodies cease to change.[22]" https://en.wikipedia.org/wiki/Thermal_equilibriumAn explicit distinction between 'thermal equilibrium' and 'thermodynamic equilibrium' is made by C.J. Adkins. He allows that two systems might be allowed to exchange heat but be constrained from exchanging work; they will naturally exchange heat till they have equal temperatures, and reach thermal equilibrium, but in general, will not be in thermodynamic equilibrium. They can reach thermodynamic equilibrium when they are allowed also to exchange work.[23]Another explicit distinction between 'thermal equilibrium' and 'thermodynamic equilibrium' is made by B. C. Eu. He considers two systems in thermal contact, one a thermometer, the other a system in which several irreversible processes are occurring. He considers the case in which, over the time scale of interest, it happens that both the thermometer reading and the irreversible processes are steady. Then there is thermal equilibrium without thermodynamic equilibrium. Eu proposes consequently that the zeroth law of thermodynamics can be considered to apply even when thermodynamic equilibrium is not present; also he proposes that if changes are occurring so fast that a steady temperature cannot be defined, then "it is no longer possible to describe the process by means of a thermodynamic formalism. In other words, thermodynamics has no meaning for such a process."[24]
so you could define a quasi-instantaneous equilibrium during a nuclear explosion. What would be the point?
That's all a bit weak. "measurable rate" and "time scale of interest" can be whatever you choose, so you could define a quasi-instantaneous equilibrium during a nuclear explosion. What would be the point?
The question is, which object is the hottest?
They show that the concept of temperature is not as well defined as some of us might have thought.
Quote from: hamdani yusuf on 08/09/2024 13:53:52The question is, which object is the hottest? The electrons in the LED with an energy of a few electron volts, corresponding to a temperature of tens of thousands of kelvin.
That doesn't mean we don't understand temperature.It means that we understand that there are things to which it does not apply.
Quote from: hamdani yusuf on 08/09/2024 13:44:43They show that the concept of temperature is not as well defined as some of us might have thought.No. It shows that the source of the quotation doesn't understand the definition. Probably a "philosopher of science".
What's temperature?QuoteTemperature is a physical quantity that quantitatively expresses the attribute of hotness or coldness. Temperature is measured with a thermometer. It reflects the average kinetic energy of the vibrating and colliding atoms making up a substance.https://en.m.wikipedia.org/wiki/TemperatureThe article above also mention kinetic temperature and internal temperature.In contrast,QuoteThermodynamic temperature is a quantity defined in thermodynamics as distinct from kinetic theory or statistical mechanics.
Quote from: Bored chemist on 09/09/2024 11:29:55Quote from: hamdani yusuf on 08/09/2024 13:53:52The question is, which object is the hottest? The electrons in the LED with an energy of a few electron volts, corresponding to a temperature of tens of thousands of kelvin.Does it melt?
Quote from: Bored chemist on 09/09/2024 11:34:13That doesn't mean we don't understand temperature.It means that we understand that there are things to which it does not apply.Can you describe what those things are?
How many times must I point out that the vibrational, rotational and electronic energies are also involved?If they don't all agree (i.e. if the equipartition principle isn't obeyed) then the temperature is not defined.