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

Check what you understood with a short quiz.

Classify mixtures by whether every small sample looks the same. Use examples like salt water, air, soil, and salad dressing to tell homogeneous mixtures from heterogeneous ones.

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

Choose a physical property that can separate a mixture, such as particle size, boiling point, magnetism, solubility, or density. Connect common methods like filtration, evaporation, distillation, and decanting to the property they exploit.

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

Check what you understood with a short quiz.

Predict whether a substance will hold its shape and volume as a solid, liquid, or gas. Use the spacing and motion of particles as a simple model for why each state behaves differently.

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

Trace melting, freezing, boiling, condensation, sublimation, and deposition as changes of state. Recognize that the substance’s identity stays the same even when its form changes.

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

Check what you understood with a short quiz.

Decide whether a property can be observed without changing the substance’s identity. Compare physical properties like color, density, and melting point with chemical properties like flammability and reactivity.

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

Use evidence such as gas formation, precipitate formation, color change, heat or light production, and odor change to suspect a chemical change. Practice checking whether those clues really mean a new substance formed.

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

Check what you understood with a short quiz.

Follow mass before and after a physical or chemical change to see what must stay constant in a closed system. Reason through why apparent mass changes often mean matter escaped, entered, or was not measured.

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

Turn descriptions into qualitative observations and measured values into quantitative data. Practice writing observations so another person could check them instead of relying on vague impressions.

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

Check what you understood with a short quiz.

Read common SI and metric units for length, mass, volume, temperature, and amount. Match prefixes like kilo-, centi-, milli-, and micro- to powers of ten so measurements can be compared.

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

Use dimensional analysis to convert a measurement without changing what it represents. Set up conversion factors so unwanted units cancel and the target unit remains.

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

Check what you understood with a short quiz.

Choose appropriate units for mass, volume, length, and temperature in chemistry problems. Distinguish base units from derived units such as cm³, mL, and g/mL.

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

Use density as a bridge between mass and volume. Calculate density, mass, or volume from the other two values and use density to compare substances or predict floating and sinking.

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

Check what you understood with a short quiz.

Convert between Celsius and Kelvin and interpret what each scale is useful for. Recognize that Kelvin measures temperature from absolute zero while Celsius is convenient for everyday laboratory temperatures.

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

Record a measured value with all certain digits plus one estimated digit. Use the smallest marks on an instrument to decide the uncertainty that belongs with the number.

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

Check what you understood with a short quiz.

Compare accuracy, precision, and percent error using repeated measurements. Decide whether a data set is close to the accepted value, tightly clustered, both, or neither.

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

Identify significant figures in measured values, including zeros that do or do not count. Round calculated answers so they do not claim more certainty than the measurements support.

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

Check what you understood with a short quiz.

Rewrite very large or very small measurements using scientific notation. Use powers of ten to compare quantities and make calculator work less error-prone.

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.