Three crystalline solids—labeled X, Y, and Z—were examined in the laboratory. The following macroscopic properties were measured.
Property | Solid X | Solid Y | Solid Z
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Melting point / °C | 1450 | 62 | 925
Hardness (Mohs scale) | 6 | 1 | 4
Electrical conductivity (solid) | None | None | High
Electrical conductivity (molten)| High | None | High
Malleability | Brittle | Soft | Malleable
(a) Identify the predominant type of chemical bonding present in each solid (ionic, metallic, or covalent molecular).
(b) For Solid X, choose one measured property and describe how that property is consistent with the bonding type you assigned in part (a).
(c) Predict whether Solid Y is likely to be soluble in a non-polar liquid such as hexane. Explain your reasoning in terms of intermolecular forces.
(d) Solid Z is observed to deform under pressure rather than fracture. Explain, at the particulate level, how its bonding and structure allow this macroscopic behavior.