Absolute Zero: Definition, Behavior of Gasses and Equations

Absolute zero temperature is the measure at which a particle experiences the least amount of temperature. Because it is zero on the Kelvin scale, an absolute zero is also known as the zero kelvin. Absolute zero has a temperature of 459.76 degrees Fahrenheit and a temperature of – 273.15 degrees Celsius. According to thermodynamics, the temperature of an object/particle depends on the velocity at which the atoms and molecules of the object oscillate. It is the lowest temperature however, it is not the lowest enthalpy state. 

Read more: Angular Momentum

KeyTerms: Absolute zero, Enthalpy, Kelvin, Gas particles, Ideal gas, Thermometer

---

Temperature

[Click Here for Sample Questions]

In physics, temperature is regarded as the physical quantity employed to measure the hot or coldness of a substance. It represents thermal energy of the body/object. The SI unit of the temperature is Kelvin. Heat and temperature are not the same. Every field uses temperature as a fundamental measuring metric. A tool used to gauge temperature is a thermometer. Scales to temperature are as follows.

• Celsius Scale (⁰C)
• Fahrenheit Scale (⁰F)
• Kelvin Scale (K)

---

Absolute Zero

[Click Here for Sample Questions]

The lowest temperature at which a substance can exist without any heat energy is absolute zero. Given that it is zero on the Kelvin scale, absolute zero is often referred to as zero kelvin temperature. Fundamental elements of nature exhibit minimal vibrational motion at this temperature.

The temperature of absolute zero is a theoretical metric. The following are some notable temperature records:

• The National Institute of Standards and Technology set a record-low temperature of 700 nK (billions of kelvin) in 1994. (NIST).
• The Massachusetts Institute of Technology (MIT) recorded a temperature of 0.45 nK (billions of kelvin) in 2003.

---

Behavior of Gasses at Absolute Zero

[Click Here for Sample Questions]

As particles of gas start to slow down, temperature gets colder. The particles cease to move at absolute zero, but they still contain energy. The only quantum mechanical, zero-point energy-induced particle motion that molecules and atoms of matter retain is the lowest vibrational motion.

According to Heisenberg’s uncertainty principle, precise measurements of subatomic particles are impossible. A particle cannot be entirely stopped in order to determine its precise position and momentum. Hence, it is not feasible to have an enthalpy level lower than absolute zero.

The behavior of a gas at various temperatures are as follows:

• At lower temperatures, gasses compress as temperature reduces. 
• At constant pressure, ideal gas reaches zero volume. 
• At a certain temperature above absolute zero, real gas condenses to a liquid or a solid.
• Ideal gas law helps to predict the behavior of real gas. 

---

Absolute Zero Formulas 

[Click Here for Sample Questions]

The most important component of a measuring instrument like a thermometer is the temperature scale. The zero degree mark is the scale's starting point. The freezing point is 0 degrees, whereas the boiling point is 100 degrees.

The Rankine (R) scale is the absolute scale that corresponds to the Fahrenheit scale. Both the Celsius and Fahrenheit scales' zero points denote the identical physical state. The relationships between the relative and absolute temperature scales are given by the equations below:

Kelvin to Celsius 

K = °C + 273.15

°C = K – 273.15

Rankine to Fahrenheit

R = °F + 460

°F = R – 460

Read more: Vapor Pressure 

---

Things to remember 

• An absolute zero is also known as the zero kelvin.
• Absolute zero has a temperature of 459.76 degrees Fahrenheit.
• Absolute zero has a temperature of – 273.15 degrees Celsius. 
• It is the lowest temperature however, it is not the lowest enthalpy state. 
• The SI unit of the temperature is Kelvin. 
• Ideal gas law helps to predict the behavior of real gas.