[eeklor]

So we have four unknown crystals - they are all solid.
My group and I have to conduct a few tests in order to figure out which crystal is an ionic crystal, which is a metal crystal, which is a covalent(network) crystal and which is a molecular crystal (polar or non-polar).

We know the basic properties of each one, but cannot figure out ways to test and distinguish one from another based on those properties.
Does anyone have some hints or ideas as to what we should test? Perhaps a link to a lab procedure similiar to this?

Thanks in advance!

[Borek]

We know the basic properties of each one

List them.

[eeklor]

Metallic Solid- a solid that consists of positive cores of atoms held together by a surrounding “sea” of
electrons. In this type of bonding, delocalized electrons surround positively charged atomic cores. This
makes them good conductors. Most metals are very hard, malleable, and ductile.

Ionic Solid- a solid that consists of cations and anions held together by the electrical attraction of
opposite charges. Ionic bonding occurs between atoms of very different electronegativities. Electrons are
not shared. The two ions are held together by electrostatic attraction.

Covalent Network Solid- A solid that consists of atoms held together in large networks or chains by
covalent bonds. Picture one huge molecule. Network solids are very hard and have very high melting and
boiling points. The electrons in a network solid are localized. This makes network solids poor conductors.

Molecular Crystals: Can be polar or non polar.. Polar ones are fragile and are soluble in water. Non polar ones are soft, and are soluble in non polar solvents such as ethers, hexane.

[Borek]

What will happen if you try to hit a crystal with hammer? If you will check its solubility? Conductance? Hardness? Melting point?

Others must help you now, I am going to sleep, it is already 1 a.m. here