Question

List the three basic subtypes of atomic solids. What kinds of forces hold each of these subtypes together?

Short answer

The three basic subtypes of atomic solids are metallic solids, ionic solids, and covalent or network solids. Metallic solids are held together by metallic bonds, ionic solids by ionic bonds, and covalent solids by covalent bonds.

Step-by-step solution

Identify the Three Basic Subtypes of Atomic Solids

The first step is to list the three basic subtypes of atomic solids, which are: metallic solids, ionic solids, and covalent or network solids.

Describe the Forces in Metallic Solids

In metallic solids, the atoms are held together by metallic bonds. These bonds are formed by a sea of delocalized valence electrons shared among the positively charged metal cations.

Describe the Forces in Ionic Solids

Ionic solids are held together by ionic bonds. These bonds are formed between positively charged cations and negatively charged anions. The electrostatic forces between the oppositely charged ions hold the solid together.

Describe the Forces in Covalent or Network Solids

Covalent or network solids are held together by covalent bonds. Atoms in these solids are connected by a network of covalent bonds, creating a rigid, extended structure.

Key concepts

Metallic Solids

Metallic solids are a type of atomic solid characterized by their unique bond type: metallic bonding.

In these solids, metal atoms release some of their outer electrons, forming what is known as a 'sea of electrons' that flows freely throughout the entire structure. This sea of delocalized electrons results from the metal atoms' nuclei, which remain fixed in a lattice. The lattice is held together by the strong electrostatic forces between the positively charged atomic cores, known as cations, and the sea of negatively charged electrons.

Properties of Metallic Solids

As a result of metallic bonding, these solids exhibit distinct properties:

• Good electrical and thermal conductivity, due to the mobile electrons.
• Malleability and ductility, allowing them to be shaped and stretched without breaking.
• A shiny, metallic luster, reflective of the way electrons interact with light within this 'sea'.

The physical properties lend metallic solids to a wide range of applications, from constructing buildings to conducting electricity in electronic devices.

Ionic Solids

Ionic solids form through the electrostatic attraction between ions, which are atoms or molecules that have lost or gained electrons and thus have a net charge.

Ionic bonds are the glue that holds these solids together, with each positively charged cation typically paired with a negatively charged anion. The result is a repeating 3D crystal lattice structure that extends in all directions, contributing to the high melting and boiling points of ionic solids.

Characteristics of Ionic Solids

Key features include:

• High melting and boiling points due to strong ionic bonds.
• Poor electrical conductivity in solid form, yet when melted or dissolved in water, they can conduct electricity due to the mobility of the ions.
• Brittleness, as shifting layers in the lattice can cause like-charged ions to repel each other and cleave the solid apart.

This brittleness and the distinct melting point of these solids are critical in applications ranging from table salt (sodium chloride) to the intricate lattice structures found in many minerals.

Covalent Network Solids

Covalent network solids, also known as network solids, are a striking subclass of atomic solids distinguished by their extensive network of covalent bonds.

These bonds form between non-metal atoms, which share electrons to achieve stability, resulting in a vast, interconnected structure. This strong bond formation leads to some of the hardest and most durable materials known, such as diamonds (a form of carbon) and quartz (silicon dioxide).

Attributes of Covalent Network Solids

Their architecture gives rise to distinctive properties:

• Hardness and high melting points, due to the strength of the covalent bonds.
• Poor electrical conductivity, as all electrons are localized in bonds and not free to move.
• Transparency in some cases, such as in diamond, where the orderly arrangement of atoms allows light to pass through with minimal scattering.

Covalent network solids are not only prized for their beauty and hardness but also play critical roles in technology, from cutting tools to semiconductor substrates in electronics.