Please answer the following chemistry questions regarding chemical separation, conductivity, and bonding properties.

Heat the mixture gently. Ammonium chloride ($\text{NH}_4\text{Cl}$) will sublime (change directly from solid to gas) and can be collected by deposition on a cool surface.

Add water to the remaining mixture (sodium chloride and silver chloride). Sodium chloride ($\text{NaCl}$) is soluble in water, while silver chloride ($\text{AgCl}$) is insoluble. Stir the mixture to dissolve the NaCl. Filter the mixture to separate the insoluble silver chloride as a residue.

Heat the filtrate (sodium chloride solution) to evaporate the water. Sodium chloride will be left behind as a solid.

5. Which particles conduct electricity in:

a) Molten lead (II) bromide
Ions ($\text{Pb}^{2+}$ and $\text{Br}^{-}$)

b) Lead metal
Delocalized electrons

6. The information in the table below relates to the physical properties of the chlorides of certain elements.

a) Explain why melting points of $\text{NaCl}$ and $\text{MgCl}_2$ are higher than those of $\text{SiCl}_4$, $\text{PCl}_3$ and $\text{SCl}_2$ chlorides in the table above.
$\text{NaCl}$ and $\text{MgCl}_2$ are ionic compounds with strong electrostatic forces of attraction between oppositely charged ions in a giant ionic lattice structure. A large amount of energy is required to overcome these strong forces, resulting in high melting points.
$\text{SiCl}_4$, $\text{PCl}_3$, and $\text{SCl}_2$ are covalent compounds that exist as simple discrete molecules. The forces between these molecules are weak intermolecular forces (van der Waals forces). Only a small amount of energy is required to overcome these weak forces, leading to low melting points.