Question

On the basis of the smaller units that make up the crystals, cite three types of crystalline solids. For each type of crystalline solid, give an example of a substance that forms that type of solid.

Short answer

Three types of crystalline solids are: 1. Ionic solid: An example is Sodium Chloride ($NaCl$), in which positive and negative ions are held together by electrostatic forces. 2. Covalent network solid: An example is Diamond ($C$), consisting of atoms connected through covalent bonds forming a rigid network. 3. Molecular solid: An example is solid $H_{2}O$ (ice), where molecules are held together by intermolecular forces, such as hydrogen bonds.

Step-by-step solution

Identify the first type of crystalline solid

The first type of crystalline solid is an ionic solid. This type of solid consists of positive and negative ions held together by electrostatic forces (ionic bonds). These solids typically form from a combination of metals and non-metals.

Provide an example of an ionic solid

An example of an ionic solid is Sodium Chloride ($NaCl$), which is common table salt. The $N{a}^{+}$ (sodium) ions and the $C{l}^{-}$ (chloride) ions are held together by ionic bonds, forming a crystalline solid structure.

Identify the second type of crystalline solid

The second type of crystalline solid is a covalent network solid. These solids consist of atoms connected through covalent bonds, forming a rigid network. The bonding is directional, leading to an extended network structure rather than isolated molecules.

Provide an example of a covalent network solid

An example of a covalent network solid is Diamond ($C$). Diamond is made up of carbon atoms, each of which is covalently bonded to four other carbon atoms in a tetrahedral structure, creating a strong and rigid network.

Identify the third type of crystalline solid

The third type of crystalline solid is a molecular solid. Molecular solids consist of molecules held together by intermolecular forces, such as hydrogen bonding, dipole-dipole interactions, and London dispersion forces. These solids are generally formed by non-metal elements.

Provide an example of a molecular solid

An example of a molecular solid is solid $H_{2}O$ (ice). The water molecules are linked together by hydrogen bonds, forming a crystalline structure.