Learning Resource Type

Learning Activity

Molecule Drawings

Subject Area

Science

Grade(s)

8

Overview

In this activity, students work in groups to draw molecules showing the individual atoms in a chemical formula.

This activity was created as a result of the ALEX Resource Development Summit.

    Science (2015) Grade(s): 8

    SC15.8.1

    Analyze patterns within the periodic table to construct models (e.g., molecular-level models, including drawings; computer representations) that illustrate the structure, composition, and characteristics of atoms and molecules.

    Unpacked Content

    UP:SC15.8.1

    Vocabulary

    • Element
    • Atom
    • Protons
    • Nucleus
    • Electrons
    • Neutrons
    • Atomic number
    • Periodic table
    • Array
    • Atomic mass
    • Period
    • Group
    • Chemical properties
    • Physical properties
    • Molecule
    • Bond
    • Chemical bond
    • Valence electron
    • Ion
    • Ionic bond
    • Nonmetal
    • Metal
    • Covalent bond
    • Metallic bond
    • Conductivity

    Knowledge

    Students know:
    • Elements are substances composed of only one type of atom each having an identical number of protons in each nucleus.
    • Atoms are the basic units of matter and the defining structure of elements.
    • Atoms are made up of three particles: protons, neutrons and electrons.
    • The number of protons in an atom's nucleus is equal to the atomic number.
    • The periodic table arranges all the known elements in an informative array.
    • Elements are arranged left to right and top to bottom in order of increasing atomic number. Order generally coincides with increasing atomic mass.
    • Rows in the periodic table are called periods. As one moves from left to right in a given period, the chemical properties of the elements slowly change.
    • Columns in the periodic table are called groups. Elements in a given group in the periodic table share many similar chemical and physical properties.
    • The period number of an element signifies the highest energy level an electron in that element occupies (in the unexcited state). The number of electrons in a period increases as one traverses down the periodic table; therefore, as the energy level of the atom increases, the number of energy sub-levels per energy level increases.
    • A molecule is formed when two or more atoms bond together chemically.
    • A chemical bond is the result of different behaviors of the outermost or valence electrons of atoms.
    • Ionic bonds are the result of an attraction between ions that have opposite charges. Ionic bonds usually form between metals and nonmetals; elements that participate in ionic bonds are often from opposite ends of the periodic table. One example of a molecule that contains an ionic bond is table salt, NaCl.
    • Covalent bonds form when electrons are shared between atoms rather than transferred from one atom to another. The two bonds in a molecule of carbon dioxide, CO2, are covalent bonds.
    • Metallic bonds exist only in metals, such as aluminum, gold, copper, and iron. In metals, each atom is bonded to several other metal atoms, and their electrons are free to move throughout the metal structure. This special situation is responsible for the unique properties of metals, such as their high conductivity.

    Skills

    Students are able to:
    • Analyze patterns within the periodic table to construct models of atomic and molecular structure, composition, and characteristics.
    • Identify the relevant components of the atomic and molecular models.
    • Describe relationships between components of the atomic and molecular models.

    Understanding

    Students understand that:
    • Patterns in the periodic table predict characteristic properties of elements. These trends exist because of the similar atomic structure of the elements within their respective group families or periods, and because of the periodic nature of the elements.
    • The structure, composition, and characteristics of atoms and molecules are dependent upon their position in the periodic table.

    Scientific and Engineering Practices

    Developing and Using Models

    Crosscutting Concepts

    Patterns

    Phase

    During/Explore/Explain
    Learning Objectives

    Learning Objectives

    Given a chemical formula, students will be able to draw a model of an assigned molecule.

    Activity Details

    1.  Students view the video clip Molecules.

    2.  Student groups choose Molecule Cards from a bag. The groups use a periodic table to identify which atoms make the molecule.

    3.  Student groups draw a model of the chosen molecule using the white paper, colored pencils/markers, and round objects for tracing circles. 

    4.  Students use a color key for the most common elements:

      • hydrogen=red
      • sodium=purple
      • oxygen=blue
      • nitrogen=yellow
      • chlorine=green
      • carbon=black

    5.  Students need to add to their color key for additional elements in their formulas.

    6.  Using digital devices with internet access, students research to identify the uses of their chosen molecule. This information is added to the group drawings.

    Assessment Strategies

    Assessment Strategies

    Student drawings are evaluated using the following criteria:

    • the correct number of atoms of each element in the formula drawn and labeled.
    • uses of the molecule identified/illustrated.

    Variation Tips

    Individual students draw their own models. Students who have the same molecule compare their finished drawings and collaborate on researching uses.

    Background and Preparation

    Background / Preparation

    The Molecule Cards can be laminated for longer use.

    A bag, box, or envelope is needed to so students can draw cards randomly.

    Digital Tools / Resources

    ALSDE LOGO