chemistry

Network solid

Network solid is a chemistry topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Network solid rather than just read about it. In short: A network solid or covalent network solid (also called atomic crystalline solids or giant covalent structures) 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.

Key takeaways

Network solid belongs to chemistry; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Network solid to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Network solid from memory before moving on to harder problems.

Reference excerpt

A network solid or covalent network solid (also called atomic crystalline solids or giant covalent structures) 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 diamond with a continuous network of carbon atoms and silicon dioxide or quartz with a continuous three-dimensional network of SiO2 units. Graphite and the mica group of silicate minerals structurally consist of continuous two-dimensional sheets covalently bonded within the layer, with other bond types holding the layers together. Disordered network solids are termed glasses. These are typically formed on rapid cooling of melts so that little time is left for atomic ordering to occur.

Properties Hardness: Very hard, due to the strong covalent bonds throughout the lattice (deformation can be easier, however, in directions that do not require the breaking of any covalent bonds, as with flexing or sliding of sheets in graphite or mica). Melting point: High, since melting means breaking covalent bonds (rather than merely overcoming weaker intermolecular forces). Solid-phase electrical conductivity: Variable, depending on the nature of the bonding: network solids in which all electrons are used for sigma bonds (e.g. diamond, quartz) are poor conductors, as there are no delocalized electrons. However, network solids with delocalized pi bonds (e.g. graphite) or dopants can exhibit metal-like conductivity. Liquid-phase electrical conductivity: Low, as the macromolecule consists of neutral atoms, meaning that melting does not free up any new charge carriers (as it would for an ionic compound). Solubility: Generally insoluble in any solvent due to the difficulty of solvating such a large molecule.

Examples Boron nitride (BN) Diamond (carbon, C) Quartz (SiO2) Rhenium diboride (ReB2) Silicon carbide (moissanite, carborundum, SiC) Silicon (Si) Germanium (Ge) Aluminium nitride (AlN) α-tin allotrope (gray tin, Sn)

See also Bonding in solids - overview of different bonding types in solids Molecular solids - materials containing discrete molecules held together by weak intermolecular bonds Ionic solids (salts) - materials with a network of strong ionic bonds rather than covalent bonds Metals - materials held together by strong metallic bonding rather than covalent bonds Layered materials - materials with networks of strong bonds within two-dimensional sheets with much weaker bonds between the sheets Polymers - materials with strong bonds within one-dimensional chains and much weaker bonds between the chains

References

Worked examples

Example 1 — a first encounter with Network solid

Start with the simplest possible case. Write down what Network solid claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Network solid before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Network solid ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Network solid

In research: Network solid appears in chemistry research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Network solid in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Network solid is common in secondary-school and first-year university syllabi. It links to neighbouring topics Chemical bonding, so understanding it makes those chapters shorter.
In everyday life: Look for Network solid outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Network solid in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Network solid means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Network solid out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Network solid in simple terms?

Why does Network solid matter?

Because it connects several chemistry ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Network solid?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Network solid.