Covalent Bonding
Übersicht
Water, oxygen, carbon dioxide, plastics, diamond - all of these substances are held together by covalent bonds, yet their physical properties could not be more different. The key lies in whether the covalent bonds build small, individual molecules or extend into giant lattices that stretch in every direction.
This lesson explains how atoms share electron pairs to form covalent bonds, how to draw dot-and-cross diagrams for a range of molecules, and why simple molecular substances have low melting points while giant covalent structures like diamond are among the hardest materials on Earth. You will also explore graphite and C60 fullerene and learn to link structure to properties.
Ziele
- know that a covalent bond is formed between atoms by the sharing of a pair of electrons
- understand covalent bonds in terms of electrostatic attractions
- understand how to use dot-and-cross diagrams to represent covalent bonds in:
- • diatomic molecules, including hydrogen, oxygen, nitrogen, halogens and hydrogen halides - inorganic molecules including water, ammonia and carbon dioxide - organic molecules containing up to two carbon atoms, including methane, ethane, ethene and those containing halogen atoms. explain why substances with a simple molecular structures are gases or liquids, or solids with low melting and boiling points the term intermolecular forces of attraction can be used to represent all forces between molecules
- explain why the melting and boiling points of substances with simple molecular structures increase, in general, with increasing relative molecular mass
- explain why substances with giant covalent structures are solids with high melting and boiling points
- explain how the structures of diamond, graphite and C60 fullerene influence their physical properties, including electrical conductivity and hardness
- know that covalent compounds do not usually conduct electricity
Mindmap
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Lektionshinweis
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Unterrichtsbewertung
Herzlichen Glückwunsch zum Abschluss der Lektion über Covalent Bonding. Jetzt, da Sie die wichtigsten Konzepte und Ideen erkundet haben,
Sie werden auf eine Mischung verschiedener Fragetypen stoßen, darunter Multiple-Choice-Fragen, Kurzantwortfragen und Aufsatzfragen. Jede Frage ist sorgfältig ausgearbeitet, um verschiedene Aspekte Ihres Wissens und Ihrer kritischen Denkfähigkeiten zu bewerten.
Nutzen Sie diesen Bewertungsteil als Gelegenheit, Ihr Verständnis des Themas zu festigen und Bereiche zu identifizieren, in denen Sie möglicherweise zusätzlichen Lernbedarf haben.
- How many bonding pairs of electrons are in a molecule of water, H2O? A) 1 B) 2 C) 3 D) 4 Answer: B
- Which of these substances has a giant covalent structure? A) Carbon dioxide B) Water C) Diamond D) Sodium chloride Answer: C
- Why does graphite conduct electricity? A) It contains ions that are free to move B) It contains delocalised electrons that can move along the layers C) It has a low melting point D) Its covalent bonds carry charge Answer: B
- Simple molecular substances have low boiling points because: A) Their covalent bonds are weak B) Their intermolecular forces are weak C) They contain ions D) They have giant structures Answer: B
- How many carbon atoms are in one molecule of buckminsterfullerene? A) 12 B) 24 C) 60 D) 120 Answer: C
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Empfohlene Bücher
Weiterlernen mit offenen Quellen
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Lehrbuchabschnitt
Lewis Symbols and Structures
Write Lewis symbols for neutral atoms and ions
"Chemistry: Lewis Symbols and Structures" by OpenStax, OpenStax, Rice University, licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Source: https://openstax.org/books/chemistry/pages/7-3-lewis-symbols-and-structures. Access for free at https://openstax.org/books/chemistry/pages/1-introduction
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Lehrbuchabschnitt
The Solid State of Matter
Define and describe the bonding and properties of ionic, molecular, metallic, and covalent network crystalline solids
"Chemistry: The Solid State of Matter" by OpenStax, OpenStax, Rice University, licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Source: https://openstax.org/books/chemistry/pages/10-5-the-solid-state-of-matter. Access for free at https://openstax.org/books/chemistry/pages/1-introduction
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