Lattice Structure
A crystalline structure occurs when atoms are arranged into a repeating array which contain ions. This structure is repeated in three dimensions on a lattice. In the lattice structure, the anions are much larger than the cations. This causes the anions to form the crystal array. There are seven types of crystalline structures. These structures consist of triclinic, monoclinic, orthorhombic, rhombohedral, tetragonal, hexagonal and cubic. When silver bromide arranges into a crystalline structure, it forms a cubic structure. A cubic structure forms when atoms are arranged in a cube shape. Along with being the simplest shape, this shape is also the most commonly found shape in crystals and minerals. Silver bromide is found as bromargyrite which is a natural mineral. In the lattice structure of silver bromide, silver is the cation which means it is much smaller than bromine, the anion. Since silver and bromine have opposite charges, the attraction between them increases which causes them to be extremely attracted to each other. This attraction allows for both silver and bromine atoms to be tightly packed together in a cube shape. Silver bromide has a melting point of 432 °C. The melting point is high due to the fact that the ions are so strongly attracted to one another which requires a great amount of energy to break the force between atoms. The boiling point of silver bromide is 1,502 °C. It has such a high boiling point due to the fact that silver bromide has a high number of electrons which causes an increase in London dispersion forces. Another reason silver bromide has such a high melting point is because the compound is very strong and extremely condensed. Since the compound is so condense, a high boiling point is required to change it from vapour form to liquid form. The rigidity of silver bromide can be described as a soft solid. The color of silver bromide ranges from pale to yellow. Since silver bromide exists as a salt, it resists changes in shape and which in turn causes it to be inflexible. As silver and bromide join together, hydrogen bonds are unable to form. The missing presence of hydrogen bonds causes silver bromide to be insoluble in water. Silver bromide is also insoluble in water and other polar substances due to the like dissolves like theory. This theory states that like substances dissolve like substances, since water is polar and silver bromide is not polar, they cannot dissolve. Since silver bromide is an ionic compound, it does not have polar bonds because there is 100% electron transfer. Not having a polarity means silver bromide does not have dipole dipole forces. Just like everything else, silver bromide has van der waals.
