Properties of covalent substances
I can describe some different structures that non-metal atoms can form using covalent bonding and describe the properties of covalent compounds.
Properties of covalent substances
I can describe some different structures that non-metal atoms can form using covalent bonding and describe the properties of covalent compounds.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- Typical atomic radii, and bond length, are in the order of 10⁻¹⁰m.
- Non-metal elements and non-metal compounds form covalent structures.
- Simple covalent substances have no free moving charge carriers so cannot conduct electricity (some giant covalent can).
- Small molecules are usually gases or liquids with relatively low melting and boiling points.
- Giant covalent structures have high melting/boiling points because strong covalent bonds need to be broken.
Keywords
Molecule - a particle consisting of a fixed number of (two or more) non-metal atoms covalently bonded together
Covalent bond - the strong electrostatic force of attraction between a shared pair of electrons and the nuclei of bonded atoms
Intermolecular forces - the weak forces of attraction between molecules and molecular substances
Giant covalent structure - a substance that has a large regular arrangement of atoms all joined together by covalent bonds
Polymer - a long chain molecule formed by joining small molecules (monomers) together by covalent bonds
Common misconception
Pupils often think that covalent bonds are broken when any covalent structure undergoes a change of state; not just those in giant covalent structures.
Use physical models to show the difference between a simple covalent structure and a giant covalent structure. Explain that it is the weak intermolecular forces that are overcome when a simple covalent molecule changes state.
Equipment
None required.
Licence
This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Lesson video
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Starter quiz
6 Questions
