Learning Resource Type

Classroom Resource

What Is Density?

Subject Area

Science

Grade(s)

8

Overview

In this lesson, students will observe a copper and an aluminum cube of the same volume placed on a balance. They will see that the copper has a greater mass. Students will try to develop an explanation, on the molecular level, for how this can be. Students are then given cubes of different materials that all have the same volume. Students determine the density of each cube and identify the substance the cube is made from.

Students will be able to calculate the density of different cubes and use these values to identify the substance each cube is made of. Students will be able to explain that the size, mass, and arrangement of the atoms or molecules of a substance determines its density.

    Science (2015) Grade(s): 8

    SC15.8.5

    Observe and analyze characteristic properties of substances (e.g., odor, density, solubility, flammability, melting point, boiling point) before and after the substances combine to determine if a chemical reaction has occurred.

    Unpacked Content

    UP:SC15.8.5

    Vocabulary

    • Characteristic properties (e.g., odor, density, solubility, flammability, melting point, boiling point)
    • Substances
    • Chemical reaction

    Knowledge

    Students know:
    • Each pure substance has characteristic physical and chemical properties that can be used to identify it.
    • Characteristic properties of substances may include odor, density, solubility, flammability, melting point, and boiling point.
    • Chemical reactions change characteristic properties of substances.
    • Substances react chemically in characteristic ways.
    • In a chemical process, the atoms that make up the original substances are regrouped into different molecules, and these new substances have different properties from those of the reactants.

    Skills

    Students are able to:
    • Observe characteristic physical and chemical properties of pure substances before and after they interact.
    • Analyze characteristic physical and chemical properties of pure substances before and after they interact.
    • Analyze the properties to identify patterns (i.e., similarities and differences), including the changes in physical and chemical properties of each substance before and after the interaction.
    • Use the analysis to determine whether a chemical reaction has occurred.

    Understanding

    Students understand that:
    • Observations and analyses can be used to determine whether a chemical reaction has occurred.
    • The change in properties of substances is related to the rearrangement of atoms in the reactants and products in a chemical reaction (e.g., when a reaction has occurred, atoms from the substances present before the interaction must have been rearranged into new configurations, resulting in the properties of new substances).

    Scientific and Engineering Practices

    Analyzing and Interpreting Data

    Crosscutting Concepts

    Patterns
    Link to Resource

    CR Resource Type

    Lesson/Unit Plan

    Resource Provider

    Other

    Resource Provider other

    American Chemical Society
    Accessibility

    Accessibility

    Video resources: includes closed captioning or subtitles
    License

    License Type

    CUSTOM
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