# Condensed matter - Is quantum effects relevant.

1. Oct 21, 2012

### dikmikkel

a) Are quantum effects relevant for the air around us?

"Formulas":
The Fermi energy of athmosperic air:
$\epsilon_F = \dfrac{\hbar^2}{2m_{air}}(3\pi^2C)^{2/3}$

Attempt to solve:
I calculated the fermi energy to : $\epsilon_F = 1\times 10^{-25}\,\text{J}$
And $k_bT = k_b 293\,\text{K} = 4\times 10^{-21}\,\text{J}$
The fermi energy is orders of magnutide smaller than kbT, and thus the quantum effects are not relevant.

Question:
What is the physical meaning of the term $k_bT$