Question

Estimate the average thermal energy of a helium atom at (i) room temperature (27 °C), (ii) the temperature on the surface of the Sun (6000 K), (iii) the temperature of 10 million Kelvin (the typical core temperature in the case of a star).

Answer 1

At room temperature, T = 27°C = 300 K

Average thermal energy = (3/2)kT

Where k is Boltzmann constant = 1.38 × 10^–23 m² kg s^–2 K^–1 

Hence, the average thermal energy of a helium atom at room temperature (27°C) is 6.21 × 10^–21 J.

Hence, the average thermal energy of a helium atom on the surface of the sun is 1.241 × 10^–19 J.

At temperature, T = 10⁷ K

Hence, the average thermal energy of a helium atom at the core of a star is 2.07 × 10^–16 J.