Question

The boiling point of liquid hydrogen is 20.3 K at atmospheric pressure. What is this temperature on
(a) the Celsius scale and
(b) the Fahrenheit scale?

Answer 1

Temperature is a physical quantity that describes how hot or cold something is. When a body comes into contact with another that is cooler or cooler, it is the origin of thermal energy, which is inherent in all matters and is the cause of the occurrence of heat, a flow of energy.

Formula used:
$F = \dfrac{9}{5}C + 32$
${T_K} = {T_C} + 273.15$

Complete answer:
The liquid state of the element hydrogen is known as liquid hydrogen. The molecular component of hydrogen,${H_2}$, is present in nature. ${H_2}$must be cooled below its critical point of 33 K to survive as a liquid.
A substance's boiling point is the temperature at which the vapour pressure of a liquid equals the pressure surrounding the liquid and the liquid transforms into a vapour. The boiling point of a liquid is affected by the surrounding atmospheric pressure.
The degree Celsius (symbol: $^\circ C$) may refer to a particular temperature on the Celsius scale or a unit used to denote a temperature difference or spectrum. It was named after Anders Celsius (1701–1744), a Swedish astronomer who created a similar temperature scale.
The Fahrenheit scale is based on a temperature scale proposed by physicist Daniel Gabriel Fahrenheit in 1724. The temperature is measured in degrees Fahrenheit.
The kelvin is the SI's (International System of Units) base unit of temperature, denoted by the letter K. It is named after William Thomson, 1st Baron Kelvin (1824–1907), a Belfast-born Glasgow University engineer and physicist.
Kelvin to Celsius
${{\text{T}}_{\text{C}}} = {\text{T}} - 273.15$
T = 20.3 K
${{\text{T}}_{\text{C}}} = {\text{T}} - 273.15 = 20.3\;{\text{K}} - 273.15\;{\text{K}} = - {253^0}{\text{C}}$
$\Rightarrow {{\text{T}}_{\text{C}}} = - {253^0}{\text{C}}$
Celsius to Fahrenheit
$F = \dfrac{9}{5}C + 32$
${{\text{T}}_{\text{F}}} = \dfrac{9}{5}\;{{\text{T}}_{\text{c}}} + {32^0}\;{\text{F}} = \dfrac{9}{5}\left( { - {\mathbf{25}}{{\mathbf{3}}^0}{\text{C}}} \right) + {32^0}\;{\text{F}} = - {423^0}\;{\text{F}}$
$\Rightarrow {{\text{T}}_{\text{F}}} = - {423^0}\;{\text{F}}$

Note:
A thermometer is used to determine the temperature. Thermometers are calibrated in a variety of temperature ranges that have traditionally defined temperature using a variety of reference points and thermometric substances. The Celsius scale (formerly known as centigrade, denoted as $^\circ C$), the Fahrenheit scale (denoted as $^\circ F$), and the Kelvin scale (denoted as K) are the most common scales. The Kelvin scale (denoted as K) is mostly used for scientific purposes under conventions of the International System of Units (SI).