## Perfect Crystal in terms of Entropy

$\Delta S = \frac{q_{rev}}{T}$

PeterTran1C
Posts: 30
Joined: Thu Jul 13, 2017 3:00 am

### Perfect Crystal in terms of Entropy

I was wondering what the connection was between Entropy and the idea of a perfect crystal. I remember writing down how a perfect crystal has no impurities, no defects and can be cooled down to 0 K, but does this have to do with Entropy directly?

Amanda Mac 1C
Posts: 58
Joined: Fri Sep 29, 2017 7:05 am

### Re: Perfect Crystal in terms of Entropy

I think that in terms of entropy, a perfect crystal has entropy=0 because all the molecules are lined up perfectly. All the molecules are uniform and no matter how you arrange the molecules, they'll still fit perfectly. Since this is true, there is no "disorder" and this foundation makes up the basis of the third law of thermodynamics. Hope this helped!

Rana YT 2L
Posts: 49
Joined: Thu Jul 27, 2017 3:01 am

### Re: Perfect Crystal in terms of Entropy

in addition, Dr. Lavelle mentioned in lecture that an entropy=0 can only occur when the temperature is at 0 K.