Question

Please provide a detailed explanation of how to tell the following apart:

molecular solids

ionic solids

atomic solids

nonbonding atomic solids

metallic atomic solids

network covalent atomic solids

Answer 1

Molecular solids are solids that are essentially collections of molecules held together by intermolecular forces (IMFs). The solid structure is maintained by IMFs rather than bonds (metallic, covalent, or ionic). The forces holding the solids together are much weaker than for other types of solids. As a result these materials have much lower melting points. Molecular solids also have localized electrons (localized within the bonds in each molecule) and as such, do not conduct electricity.

Examples include ice (solid water), dry ice (solid CO2), solid iodine, and napthalene to name a few.

Ionic Solids are solids composed of oppositely charged ions. They consist of positively charged cations and negatively charged anions .When Ionic Solids are dissolved in water the cations and the anions separate, they become free to move about in the water allowing the solution to conduct electrical current.

Example: NaCl which is formed by the transfer of electronsbetween Na and Cl in which Na forms a cation (Na+) and an anion(Cl-)

atomic solids—Made up of atoms connected by covalent bonds; the intermolecular forces are covalent bonds as well. Characterized as being very hard with very high melting points and being poor conductors. Examples of this type of solid are diamond and graphite, and the fullerenes.

Nonbonding atomic solids, such as solid xenon, are held together by relatively weak dispersion forces. Xenon atoms have stable electron configurations and therefore do not form covalent bonds with each other. Consequently, solid xenon, like other nonbonding atomic solids, has a very low melting point (about −112 °C).

Metallic solids such as crystals of copper, aluminum, and iron are formed by metal atoms. The structure of metallic crystals is often described as a uniform distribution of atomic nuclei within a “sea” of delocalized electrons. The atoms within such a metallic solid are held together by a unique force known as metallic bonding that gives rise to many useful and varied bulk properties. All exhibit high thermal and electrical conductivity, metallic luster, and malleability. Many are very hard and quite strong. Because of their malleability (the ability to deform under pressure or hammering), they do not shatter and, therefore, make useful construction materials.

A network solid or covalent network solid is a chemical compound (or element) in which the atoms are bonded by covalent bonds in a continuous network extending throughout the material. In a network solid there are no individual molecules, and the entire crystal or amorphous solid may be considered a macromolecule. Formulas for network solids, like those for ionic compounds, are simple ratios of the component atoms represented by a formula unit.

Examples of network solids include diamondwith a continuous network of carbon atoms and silicon dioxide or quartz with a continuous three-dimensional network of SiO2units