Why does arsenic sublimate, while gallium melts?

[Tiiba]

What does it tell you about a substance? A height melting and boiling point means that the molecules hold together strongly, as in tungsten. A low melting point, as in hydrogen, means they're kinda loose. But what does the distance between them tell you?

Something something entropy yadda yadda enthalpy. But what?

 

[snorkack]

I'd say it says something about covalent or noncovalent nature of the bonds.
If the bonds are covalent and directional, then break them enough as to break down the long range order and you've broken mostly all of them.
If bonds are noncovalent, nearest neighbour interactions, you can break a few of them and allow atoms to slide from one nearest neighbour to another while still being bound in the liquid.