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absolute temperature means

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In physics 'absolute' refers to a set value.  Absolute zero is the lowest imaginable temperature; if we consider the molecular structure of ice versus steam we would see the water molecules in steam move much more quickly than in ice.  Where measuring temperature in Celsius compares with water's freezing point, absolute zero would be the temperature at which nothing moves.

As such, what should the answer be?

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How do we know that absolute zero is -273°C?  We can take a rigid container fitted with a pressure gauge and take pressure readings at four or five different temperatures. We can then graph pressure vs. temperature. If we extrapolate our line to 0 pressure (no molecular movement, so no collisions with container wall) we get a value of close to -273°C.

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Absolute temperature refers to Kelvin scale, used in science. There is no negative temperature in Kelvin scale, because absolute zero is the lowest possible temperature in the Universe. In Fahrenheit scale this temperature is equal to approximately - 459 0, in Celsius = - 2730 . In classical physics pressure exerted by molecules on the wall of closed volumes is zero under absolute zero temperature. In quantum mechanics it is not the case - there are slight oscillations of quantum oscillators at 00K. Some chemical reactions can take place in the Universe at extremally low temperatures very close to absolute zero. This is a result of tunnel transitions in quantum mechanics. If you have other questions regarding this issue, I'll be glad to help.

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If you recall Charles' law (thermodynamic process with constant volume), th eoriginal relationship between pressure p and temperature t in Celsius was written in the form:

                                      p(t) = p(0) ( 1+ t/273)

This is an experimentally confirmed result, where 273 is the number of degrees of Celsius. This formula states that any increase in temperature by 10C causes increase in volume by 1/273 of its original pressure p(0) (pressure for t = 00C ). If you put t = -273 0 C then p = 0. If you introduce new temperature scale with T = t + 273 0C then you will get Kelvin's temperatures with freezing point T = 273 0 K (t = 00C).

The same way, if you have isobaric process (with constant pressure) then the volume will increase by 1/273 of its original value if the increase in temperature is 10C.

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