Covalent bond: A shared pair of electrons between two non-metal atoms, formed by mutual attraction of both nuclei to the electron pair between them.
Molecule: A group of atoms held together by covalent bonds, with a fixed number of atoms and a definite composition.
Single bond: One shared pair of electrons between two atoms, represented by a single line (—).
Double bond: Two shared pairs of electrons between two atoms, represented by a double line (=). Stronger and shorter than a single bond.
Triple bond: Three shared pairs of electrons between two atoms, represented by a triple line (≡). The strongest and shortest covalent bond.
Lone pair: A pair of electrons in the outer shell of an atom that is NOT involved in bonding (also called a non-bonding pair).
This definitions covers Key Definitions 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 7 of 13 in this topic. Make sure you can use the exact wording confidently, because definition marks are often lost through vague language.
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.