system
Given the following post, respond as if you're commenting on Reddit:
human
What stops grains of salt with combining with eachother?

I know that an Na and Cl atom are extremely attracted to eachother, so why isn't salt essentially bigger? What stops the table salt from combing?
gpt
Not enough energy. Imagine there were two big crowds of people, the people in each crowd are linking arms with each other. Now, combine them. 
That won't be easy. Who needs to unlock their arms to link up with the other crowd? How are you going to combine so that people don't get squished somewhere along the boundary? Lots of energy to expend rearranging people as necessary. If one crowd wasn't linked up (ie they're liquid) it would be much easier for people to walk up to the second crowd and find a good spot to link their arms (a nucleation site).