Multiple choice

Paraffin wax is widely used on fruits and vegetables to make them shiny & to retard moisture loss and spoilage. It is an example of

  1. network covalent solids

  2. ionic solids

  3. metallic solids

  4. molecular solids

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A classic molecular solid consists of small, non-polar covalent molecules, and is held together by London dispersion forces (van der Waals forces); a classic example is paraffin wax. These forces are weak, resulting in pairwise interatomic binding energies on the order of 1/100 those of covalent, ionic, and metallic bonds. Binding energies tend to increase with increasing molecular size and polarity.