7 Written questions
6 Multiple choice questions
- Unable to conduct electricity as a solid; soluble in water; aqueous solution conducts electricity
- Insoluble: ionic compounds tend not to dissolve in nonpolar solvents because the attractions between ions are much more favorable than the attractions among the separated ions and nonpolar solvent molecules.
- Very Low: due to the strong Coulombic interactions of positive and negative ions arranged in a regular three-dimensional array.
- Poor: ionic lattices are rigid and once broken tend to cleave along an entire plane.
- Brittle: due to the repulsion of like charges caused when one layer slides across another layer.
- Non-conductive (insulators): ions are pinned by the rigid lattice.
6 True/False questions
Substitutional Alloy (properties) → formed between atoms of comparable radius, where one atom substitutes for the other in the lattice
Interstitial Alloy (properties) → formed between atoms of different radius, where the smaller atoms fill the interstitial spaces between the larger atoms
Conductivity of alloys → Non-conductive (insulators): ions are pinned by the rigid lattice.
Conductivity of a metallic solid → Good: electrons are delocalized and relatively free to move
Optical properties of metals (list and reason) → When light falls on a metal it is almost totally absorbed since the bonding electrons can jump up to a broad band of energy levels allowing energy changes corresponding to the full range of frequencies in the visible region of the spectrum.
These currents immediately re-emit the light out of the metal thus providing a strong reflection if the metal surface is smooth.
Alloys → Metallic mixtures