Determine crystalline solid type, bonding force, and rank by melting point for Os,...

1. Identify the type of crystalline solid and bonding force for Osmium (Os): Osmium is a transition metal. Metals form metallic solids where metal atoms are held together by metallic bonds (a sea of delocalized electrons). Therefore, Os forms a metallic solid with metallic bonds.

1. Identify the type of crystalline solid and bonding force for Hydrogen Chloride (HCl): HCl is a polar molecule. In the solid state, polar molecules form molecular solids held together by dipole-dipole intermolecular forces. Therefore, HCl forms a molecular solid with dipole-dipole forces.

1. Identify the type of crystalline solid and bonding force for Nitrogen (N2): N2 is a nonpolar diatomic molecule. In the solid state, nonpolar molecules form molecular solids held together by London dispersion forces (a type of van der Waals force). Therefore, N2 forms a molecular solid with London dispersion forces.

4. Determine the relative melting points:
- Metallic solids, especially those of transition metals like Osmium, generally have very high melting points due to the strong metallic bonding.
- Molecular solids have relatively low melting points. The strength of intermolecular forces determines the melting point within molecular solids. Dipole-dipole forces are generally stronger than London dispersion forces.
- Therefore, the order of melting points from highest to lowest is expected to be: Osmium (metallic) > Hydrogen Chloride (dipole-dipole) > Nitrogen (London dispersion).

5. Rank the solids in order of decreasing melting point:
- The solid with the highest melting point is Osmium, so it gets rank "1".
- The solid with the next highest melting point is Hydrogen Chloride, so it gets rank "2".
- The solid with the lowest melting point is Nitrogen, so it gets rank "3".