In the area of science, we find many important definitions related to the area of **physics** . One of them is the physical **constant** , which represents the **value of** a **physical ****quantity** whose value is fixed in a certain system of **units** and which invariably prevails during **physical processes** over time. There are many physical constants, one of them is known as **Boltzmann’s constant** .

## What is Boltzmann’s constant?

Boltzmann’s constant is a constant that is responsible for **relating** the **temperature** with **energy** and also studied the **heat** with the relationship it has with other **types** different from **energy** .

- Characteristics of the Boltzmann constant
- What is the Boltzmann constant for
- History
- Value
- Importance of the Boltzmann constant

## Characteristics of the Boltzmann constant

The main characteristics of Boltzmann’s constant are the following:

- It is considered as a
**proportionality**factor that occurs between the**temperature measured**in units and units of energy. - Its value in the SI is
**K = 1,38064852**(79) x 10^{-23}J / K = 1,3806504 x 10^{-16}ergs / K. - It is a constant that occurs between
**ideal gases**. - Express the relationship between the average energy of a
**particle**and its**temperature** - The constant is used in equations to describe the
**properties**that**gases**have . - Boltzmann’s constant is expressed in joules per
**kelvin**. - Boltzmann’s constant appears in many
**ways**, especially in sub – disciplines of**physics**of**thermodynamics**and**statistical mechanics.** - Boltzmann’s constant counts
**individual molecules**rather than the number of moles.

## What is the Boltzmann constant for

Boltzmann’s constant has many uses. Boltzmann’s constant is closely related to the constant **ideal gas,** since both are useful for the ideal gas law to determine the **relationship** between the **pressure** , the **volume** and the **number** of **molecules** of gas and temperature. One of them is in the area of **statistical mechanics** and is used to convert from the theoretical version of **entropy** information to **thermodynamic** entropy . It is also useful in the equation for entropy in order to provide a more mathematical explanation of it.

## History

Developed during the **1860s** and **1870s** by physicists **Ludwig Boltzmann** and **James Clerk ****Maxwell** . Although Boltzmann was able to link **entropy** and probability for the first time in 1877, this relationship was never expressed by means of a more specific **constant** until Max Planck was able to introduce ** k** for the first time offering a more

**exact**

**value**by means of the

**law**of black body

**radiation**. Before 1900, equations that included Boltzmann factors did not use any type of

**energy**per

**molecule**nor its

**constant**but instead included a constant form of gas R and a series of macroscopic energies for the

**substance**.

During the second half of the 19th century, there was **disagreement** over whether **atoms** and **molecules** were real and whether molecules that were **measured** by **atomic weights** were the same as **physical molecules** . In 2013, the UK National Physical Laboratory used microwave and acoustic resonance measurements to be able to calculate the speed of sound of a monatomic gas in a **triaxial ellipsoid** chamber and thus have a more accurate value for the constant, such as part of the revision of **the International System of Units** .

## Value

The **value** of the **constant** of Boltzmann is approximately **1.3807 x 10 ^{-23} joules per kelvin** (J · K

^{-1}). Generally value is measured using the determination of the accepted by the Boltzmann constant and is based on the value

**determination**of the

**universal constant**of the

**R gases**by a technique that measures the

**speed**of

**propagation**having an acoustic wave in

**argon**. Currently its value can also be measured by means of an application of laser absorption

**spectroscopy**.

## Importance of the Boltzmann constant

Boltzmann’s constant is important because it helps identify the **temperature** and **energy ****kinetics** relative to each **molecule** of **gas** . It also helps to clarify the relationship between an **electric current** and an **electric potential** , which results in a thermal voltage observed at the pn junction of the **semiconductors** . In addition, Boltzmann’s constant is one of the fundamental numbers that are used to be able to make a description about an essentially important relationship in **molecular thermodynamics** and **statistical mechanics** .

Because Boltzmann’s constant is expressed in terms of **energy** divided by **temperature** , it is compared to the expression for **entropy** . Boltzmann’s constant has been key to understanding how the **microstates** of a system are interrelated with its **macro- ****states** and the **proportions** in which change occurs. This essential number links the **statistical** mechanics of entropy with the classical understanding of **thermodynamic entropy** .