Merge branch 'master' into local

src/1_einstein_model.md

@@ -332,10 +332,10 @@ ax.set_ylim((0, 3));
 ## Conclusions
 
 1. The law of Dulong–Petit is an observation that all materials have $C≈3k_B$ per atom.
-2. Oscillations of atoms are *quantum*, and they *freeze out* when $k_BT \ll \hbar \omega_0$, leaving only zero-point motion.
-3. The Einstein model describes each atom in a solid as a quantum harmonic oscillator.
+2. The Einstein model describes each atom in a solid as a quantum harmonic oscillator.
+3. Therefore, oscillations of atoms are *quantum*, and they *freeze out* when $k_BT \ll \hbar \omega_0$, leaving only zero-point motion.
 4. Using the Bose–Einstein distribution, we derived the thermal energy and heat capacity per atom in the Einstein model.
-5. The Eisntein model correctly predicts that the heat capacity drops to 0 as $T\rightarrow 0$.
+5. The Einstein model correctly predicts that the heat capacity drops to 0 as $T\rightarrow 0$.
 
 
 ## Exercises