You are given two solids that look nearly alike, one of which is held together by ionic bonds and the other by van der Waals bonds. How could you tell them apart?

Question

You are given two solids that look nearly alike, one of which is held together by ionic bonds and the other by van der Waals bonds.  How could you tell them apart?

DrBob222 · Answer

One should be crystalline; the other should be amorphous and soft.