Work through the list without notes. If you cannot do a statement, follow its link, then come back. Guide = study guide; Practice = practice questions.
Understanding
- I can explain VSEPR as Coulombic repulsion between electron domains that spread as far apart as possible. (Guide: “Why electron pairs spread out”)
- I can explain why a lone pair, or a multiple bond, squeezes the neighbouring bond angles. (Guide: “Lone pairs push harder”; Practice Q4)
- I can explain why a π bond is weaker than a σ bond, and why a π bond stops rotation and allows cis and trans isomers. (Guide: “Sigma and pi bonds”; Practice Q5)
Skills
- I can count the electron domains on any atom, treating a double or triple bond as one domain. (Guide: Worked example 1; Practice Q1)
- I can name the electron-domain geometry and the molecular geometry for 2 to 6 domains, using all eleven shape names. (Guide: shapes table; Practice Q1, Q6)
- I can give ideal bond angles (180°, 120°, 109.5°, 90°) and say when the real angle is slightly smaller. (Guide: Figure 1; Practice Q4, Q5)
- I can place lone pairs correctly in trigonal bipyramidal (equatorial) and octahedral (opposite) arrangements. (Guide: “Five and six domains”, Worked example 2; Practice Q6, Q7)
- I can assign sp, sp² or sp³ to any atom with 2 to 4 domains, lone pairs included, and I know that atoms with 5 or 6 domains need only a shape. (Guide: Worked example 3; Practice Q2, Q4)
- I can count the σ and π bonds in a molecule. (Guide: Worked example 3; Practice Q4)
Reasoning
- I can compare bond lengths and bond energies using bond order and atomic radius. (Guide: “Bond order, bond length and bond energy”; Practice Q4(e))
- I can decide whether a molecule has a dipole moment by combining bond polarity with shape. (Guide: “Dipole moments”, Worked example 1; Practice Q3, Q6(c))
- I can evaluate a claim about shape or polarity, such as “every AX₂ molecule is bent”, with evidence from a Lewis diagram and VSEPR. (Practice Q7)
All ticked? Move on to Topic 3.1, Intermolecular and Interparticle Forces, or return to the course roadmap.