I think because its the only one to be liquid at normal temperatures.
In an ideal gas, there are no attractive forces between the gas molecules, and there is no rotation or vibration within the molecules. The kinetic energy of the translational motion of an ideal gas depends on its temperature. The formula for the kinetic energy of a gas defines the average kinetic energy per molecule. The kinetic energy is measured in Joules (J), and the temperature is measured in Kelvin (K).
K = average kinetic energy per molecule of gas (J)
kB = Boltzmann's constant ()
T = temperature (k)
Kinetic Energy of Gas Formula Questions:
1) Standard Temperature is defined to be . What is the average translational kinetic energy of a single molecule of an ideal gas at Standard Temperature?
Answer: The average translational kinetic energy of a molecule of an ideal gas can be found using the formula:
The average translational kinetic energy of a single molecule of an ideal gas is (Joules).
2) One mole (mol) of any substance consists of molecules (Avogadro's number). What is the translational kinetic energy of of an ideal gas at ?
Answer: The translational kinetic energy of of an ideal gas can be found by multiplying the formula for the average translational kinetic energy by the number of molecules in the sample. The number of molecules is times Avogadro's number:
Explanation:
Given parameters:
Wavelength of photon = 827nm = 827 x 10⁻⁹m
Unknown:
Energy of the photon = ?
Type of radiation = ?
Solution:
The energy of a photon can be derived using the expression below:
E = 
h is the Planck's constant = 6.63 x 10⁻³⁴m²kg/s
c is the speed of light = 3 x 10⁸m/s
Insert the parameters and solve;
E = 
E = 2.4 x 10⁻¹⁹J
Type of radiation:
Near infrared radiation
