What is a covalent bond?
1 mark · NormalWhich of the following dot-and-cross diagrams correctly represents the covalent bonding in a molecule of hydrogen chloride, HCl?
Show answer
Correct option: A. H and Cl with one shared pair and Cl with 6 additional outer electrons.
Common mistakes: Not adding enough electrons to Cl.; Drawing an incorrect number of shared pairs.
Show mark scheme and worked solution
Marking points
A1 · 1 mark · Chooses option A (one shared pair, Cl with 6 remaining outer electrons).
Worked solution
HCl forms by H sharing its only electron with Cl, which has 7 outer electrons, so one pair is shared and the other 6 electrons remain as 3 lone pairs on Cl.