20 multiple-choice questions in College Board exam style. Each has four choices and a full explanation of why each option is right or wrong.
Start with electronegativity difference. Most bonding-type questions can be answered by estimating whether the atoms involved are metal-nonmetal, nonmetal-nonmetal, or metal-metal.
Always count lone pairs before naming a shape. Electron-domain geometry and molecular geometry only match when there are zero lone pairs on the central atom.
Formal charge is a comparison tool, not a fact. Use it to choose between competing Lewis structures, not to claim a "real" charge exists on an atom.
Read the explanations even when you got it right. Each one teaches a small fact that often returns in a different form on the exam.