7 Written questions
6 Multiple choice questions
- Good: electrons are delocalized and relatively free to move
- Soluble: the charged ions interact with the dipoles on the water molecules.
- 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.
- Hard: ionic lattice is strong and rigid
- Poor: ionic lattices are rigid and once broken tend to cleave along an entire plane.
- Shiny, reflective, lustrous: because electrons move freely throughout the metal. Metals are shiny because of the very strong absorption of light by the delocalised bonding electrons.
6 True/False questions
Substitutional Alloy (definition) → density is usually between that of the component metals; alloy remains malleable and ductile
Interstitial Alloy (definition) → formed between atoms of different radius, where the smaller atoms fill the interstitial spaces between the larger atoms
Conductivity of alloys → Good: alloys usually retain a sea of mobile electrons (delocalized covalent bonds) and so remain conducting (for both HEAT and ELECTRICITY)
Surface chemistry of an alloy → Alloy formation sometimes alters the chemistry such as the formation of a chemically inert oxide layer in stainless steel.
Interstitial Alloy (properties) → formed between atoms of different radius, where the smaller atoms fill the interstitial spaces between the larger atoms
Brittleness of an ionic solid → Brittle: due to the repulsion of like charges caused when one layer slides across another layer.