This deep dive covers Understanding Different Types of Covalent Bonds within Covalent Bonding for GCSE Chemistry. Revise Covalent Bonding in Bonding & Structure for GCSE Chemistry with 25 exam-style questions and 21 flashcards. This topic appears less often, but it can still be a useful differentiator on mixed-topic papers. It is section 3 of 13 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
🔬 Understanding Different Types of Covalent Bonds
Single, Double, and Triple Bonds:
• Each atom contributes ONE electron
• Represented as a single line: H-H, H-Cl, C-H
• Examples: H₂, HCl, CH₄, H₂O
• The most common type of covalent bond
• Each atom contributes TWO electrons
• Represented as a double line: O=O, C=O
• Examples: O₂, CO₂
• Stronger and shorter than single bonds
• Each atom contributes THREE electrons
• Represented as a triple line: N≡N
• Example: N₂ (nitrogen gas)
• Very strong — this is why nitrogen is so unreactive!
Common Molecules You Must Know:
• Each H has 1 electron, needs 2 for full shell
• Share 1 electron each → 1 shared pair
• Single bond: H-H
• Both now "have" 2 electrons (like helium)
• O has 6 outer electrons, needs 8
• Each H has 1 electron, needs 2
• O shares 2 electrons (one with each H)
• Each H shares 1 electron with O
• O gets 8, each H gets 2 — everyone's happy!
• Formula shows 2 H atoms bonded to 1 O
• Each O has 6 outer electrons, needs 8
• Each O needs to gain 2 more electrons
• Solution: share 2 pairs of electrons (double bond)
• O=O (double bond)
• Both O atoms now "have" 8 electrons
• Each N has 5 outer electrons, needs 8
• Each N needs 3 more electrons
• Solution: share 3 pairs of electrons (triple bond)
• N≡N (triple bond)
• This is why nitrogen gas is so stable and unreactive!
• C has 4 outer electrons, needs 8
• Each H has 1 electron, needs 2
• C forms 4 single bonds with 4 H atoms
• C gets 8, each H gets 2
• Tetrahedral shape (3D pyramid)
Counting Tip: An atom needs to make enough bonds to complete its outer shell. H needs 1 bond (to get 2 electrons), O needs 2 bonds (to get 8), N needs 3 bonds (to get 8), C needs 4 bonds (to get 8).
Practice questions for Covalent Bonding
Which of the following best describes a covalent bond?
Explain the difference between a bonding pair and a lone pair of electrons in a covalent molecule.