What is another term for "very orderly arrangement of particles"?

Answer 1

Uh, how about, anti-entropy (just made that up).

Entropy is a measure of disorder of a system--specifically a measure of the number of states available to that system.

Something which is perfectly ordered (it can't be rearranged in any way and still be the same) has minimum entropy.

I can't think of a better word for it.

Answer 2

A Solid

(as opposed to liquid, gas, or plasma)

I hope that the answer you want!!

Answer 3

crystal