Skip to content
CHEM 121 Studioby Learn4Less · UBC CHEM 121

CHEM 121 glossary

Molecular solid

A solid made of discrete molecules held together only by intermolecular forces. It is soft, melts or sublimes at low temperature and never conducts electricity; melting it leaves the covalent bonds inside each molecule intact.

Molecular solidDiscrete molecules, each held together by strong covalent bonds, packed in a crystal and attracted to each other only by weak intermolecular forces (dotted lines), as in ice, dry ice (solid CO₂) or iodine.strong covalent bonds within molecules,weak intermolecular forces between them (dotted)low melting; soft (ice, dry ice, I₂)

Example

Iodine crystals are IX2\ce{I2} molecules held by dispersion forces; they melt at about 114 °C and give off violet vapour even at room temperature.

See alsoIntermolecular forcesCovalent-network solidIonic solidMetallic solid