Third Law of Thermodynamics

Of all the laws of thermodynamics or all the thermodynamic laws, we tend to be more familiar with the First Law Of Thermodynamics and the second law of thermodynamics more than the third law of thermodynamics. Together these laws have built the foundation of modern industries to a great extent. These laws defined are of paramount importance in the field of science and research; everything in this universe abides by them. In its simplest form, the third law of thermodynamics reads like this, the entropy or randomness of the matter is related to its absolute temperature.

Third Law Of Thermodynamics

The Third Law states, “The entropy of a perfect crystal is zero when the temperature of the crystal is equal to absolute zero (0 K).”

The third law of thermodynamics also refers to a state known as “absolute zero”. This is the lowest point on the Kelvin scale. So 0 Kelvin becomes the lowest temperature in the universe. It is -273.15^oC or -459.7^oF. But reality works differently; actually, no object or system can attain zero Kelvin, as per the second law of thermodynamics.

To get to absolute zero it requires an infinite number of steps. Getting absolute zero will violate the second law of thermodynamics. According to the Second Law Of thermodynamics, the heat cannot spontaneously move from a colder body to a hotter body. This implies that when a system approaches absolute zero it will tend to draw heat or energy from something nearby, and if this happens, it will never actually become zero.

We started with the first law of thermodynamics which talks about the conservation of energy and the fact that it can neither be created or destroyed and then moved on to the second law of thermodynamics which spoke about entropy and disorder. Finally, we moved on to the third law of thermodynamics which brought the concept of absolute zero.

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