Question

Why is boiling point of Silicon less than that of Aluminium although it has higher melting point?

Answer 1

Si is a mettaloid and has strong covalent bonds.
in solid state, due to its perfect lattice structure, it is difficult to melt it, but once it melts, it is easier to boil it.

Al on the other hand is a metal and easier to melt. However, there is more energy between the atoms of a molten Al and is difficult to boil it.