How to Use This Worksheet Work through the sections in order. Section A checks the ideas, Section B builds fluency with electron counting and standard diagrams, and Section C mixes everything the way an exam would. For every species, work in the same order: count the total valence electrons first and write the number down, … Read more
Master AP Chemistry Topic 4.4 with this free practice quiz. Test your skills on physical changes, chemical changes, and intermolecular vs intramolecular forces to prepare for your AP exam. The Particle Test: What Actually Changes Every change is classified by one question about its particles: afterwards, are the particles the same substances as before, or … Read more
What a Lewis Diagram Shows A Lewis diagram is a map of the valence electrons in a molecule or polyatomic ion. Every valence electron the species owns must appear in the diagram, either in a bonding pair, shared between two atoms, or in a lone pair, held by one atom alone. One line between two … Read more
How to Use This Worksheet Work through the sections in order. Section A checks the ideas, Section B builds fluency with atomic radii data and alloy classification, and Section C mixes everything the way an exam would. For every alloy question, work in the same order: compare the two atomic radii first and calculate the … Read more
The Electron Sea Model A solid metal is a regular lattice of positive metal ions surrounded by a sea of delocalized valence electrons. Each metal atom gives its valence electrons to the shared pool, so the electrons move throughout the whole crystal and belong to no single atom. Why the cations do not fly apart. … Read more
How to Use This Worksheet Work through the sections in order. Section A checks the ideas, Section B builds fluency with lattice data and ionic radii, and Section C mixes everything the way an exam would. For every lattice energy question, work Coulomb’s law in the same order: state the charge product first, then compare … Read more
The Ionic Lattice An ionic solid is not a collection of separate molecules. The ions pack into a crystal lattice: a regular, repeating three dimensional arrangement that extends through the whole solid. The formula, such as NaCl, gives only the lowest ratio of ions, because no individual Na⁺ belongs to any one Cl⁻. The arrangement … Read more
How to Use This Worksheet Work through the sections in order. Section A checks the ideas, Section B builds fluency with bond data and energy curves, and Section C mixes everything the way an exam would. For every curve question, read the two features separately: the horizontal position of the minimum is the bond length, … Read more
The Potential Energy Curve Bring two atoms slowly toward each other and track the potential energy of the pair. Far apart, they barely interact and the energy is near zero. As they approach, each nucleus attracts the other atom’s electrons, and the energy falls. At one specific distance the energy reaches its minimum. That distance … Read more
Master AP Chemistry Topic 4.3 with this free practice quiz. Test your skills on particulate models, limiting reactants in diagrams, and stoichiometric ratios to prepare for your AP exam. Three Representations of the Same Reaction One reaction can be represented at three levels, and exam questions move between them. The macroscopic level is what is … Read more