Use what you learned in the previous lesson to solve real-world problems.

Check what you understood with a short quiz.

Use particle pictures to separate pure substances from mixtures, and elements from compounds. Recognize when every particle is the same, when different atoms are bonded together, and when different particles are simply mixed.

Use what you learned in the previous lesson to solve real-world problems.

Reason through why opposite charges attract and like charges repel. Use simple examples like Na⁺ and Cl⁻ to predict which particles pull together and which push apart.

Use what you learned in the previous lesson to solve real-world problems.

Check what you understood with a short quiz.

Picture a chemical bond as a lasting attraction that holds particles at a workable distance, not as a physical stick or hook. Recognize that attractions and repulsions both matter when particles stay together.

Use what you learned in the previous lesson to solve real-world problems.

Read formulas such as H₂O, CO₂, NaCl, and CaCl₂ as particle information. Decide when subscripts count atoms in a molecule and when they show the simplest ratio of particles in a solid.

Use what you learned in the previous lesson to solve real-world problems.

Check what you understood with a short quiz.

Treat groups like SO₄²⁻, NO₃⁻, and NH₄⁺ as bonded atom groups that carry an overall charge. Use parentheses in formulas to keep a polyatomic ion together when more than one is needed.

Use what you learned in the previous lesson to solve real-world problems.

Combine positive and negative ions in ratios that make the total charge zero. Work through examples like MgCl₂ and Al₂O₃ to see why ionic formulas are neutral recipes, not random pairings.

Use what you learned in the previous lesson to solve real-world problems.

Check what you understood with a short quiz.

Visualize an ionic solid as a repeating three-dimensional lattice of positive and negative ions. Recognize why NaCl means a ratio throughout a crystal rather than one separate “salt molecule.”

Use what you learned in the previous lesson to solve real-world problems.

Recognize molecular substances as collections of separate molecules, each with its own fixed set of bonded atoms. Compare water, oxygen, and carbon dioxide to see how molecules can be elements or compounds.

Use what you learned in the previous lesson to solve real-world problems.

Check what you understood with a short quiz.

Separate the strong bonds that hold atoms inside a molecule from the weaker attractions that hold neighboring molecules near each other. Use liquid water or solid carbon dioxide as examples of molecules staying together as a material.

Use what you learned in the previous lesson to solve real-world problems.

Recognize covalent network solids as one giant connected structure rather than separate molecules. Use diamond, graphite, and quartz as examples where the formula gives a repeating ratio in a connected network.

Use what you learned in the previous lesson to solve real-world problems.

Check what you understood with a short quiz.

Picture metals as extended arrays of atoms held together collectively, not as separate molecules. Connect that particle arrangement to familiar metal traits such as bending, shaping, and conducting electricity.

Use what you learned in the previous lesson to solve real-world problems.

Choose between particle diagrams, ball-and-stick models, space-filling models, and lattice drawings based on what you need to show. Notice what each model makes clear and what it hides or exaggerates.

Use what you learned in the previous lesson to solve real-world problems.

Check what you understood with a short quiz.

Review this chapter with practice based on your mistakes.