Learning Resource Type

Classroom Resource

Molecule Shapes

Subject Area

Science

Grade(s)

9, 10, 11, 12

Overview

In this PhET Activity, students will model molecular shapes by creating 3D ball-and-stick images. Students will explore the effects of adding and removing bonds and/or lone pairs of electrons. Students will also utilize models of real molecules to analyze their electron and molecular geometries and bond angles. This activity can be used to introduce molecular shapes or to reinforce student knowledge.

    Science (2015) Grade(s): 09-12 - Chemistry

    SC15.CHM.3

    Use the periodic table as a systematic representation to predict properties of elements based on their valence electron arrangement.

    Unpacked Content

    UP:SC15.CHM.3

    Vocabulary

    • Protons
    • Neutrons
    • Nucleus
    • Electrons
    • Valence
    • Main group elements
    • Properties
    • Atoms
    • Elements
    • Periods/ Rows
    • Groups/ Families/ Columns
    • Atomic/ molecular level
    • Macroscopic level
    • Periodic trends
    • metal/ nonmetal/ metalloid behavior
    • electrical/ heat conductivity
    • electronegativity
    • electron affinity
    • ionization energy
    • atomic-covalent/ ionic radii
    • Molecular modeling
    • Lewis dot
    • 3-D ball-and-stick
    • space-filling
    • VSEPR
    • Types of bonds
    • ionic bonds
    • covalent/ molecular bonds
    • metallic bonds
    • Molecular shapes
    • Ions
    • Ionic compounds
    • Covalent/ molecular compounds

    Knowledge

    Students know:
    • The atom has a positively-charged nucleus, containing protons and neutrons, surrounded by negatively-charged electrons.
    • The periodic table can be used to determine the number of particles in an atom of a given element.
    • The relationship between the arrangement of main group elements on the periodic table and the pattern of valence electrons in their atoms.
    • The relationship between the arrangement of elements on the periodic table and the number of protons in their atoms.
    • The trends in relative size, reactivity, and electronegativity in atoms are based on attractions of the valence electrons to the nucleus.
    • The number and types of bonds formed (i.e. ionic, covalent, metallic) by an element and between elements are based on the arrangement of valence electrons in the atoms.
    • The shapes of molecules are based on the arrangement of valence electrons in the atoms.
    • The rules for naming chemical compounds are based upon the type of bond formed.
    • The number and charges in stable ions that form from atoms in a group of the periodic table are based on the arrangement of valence electrons in the atoms.

    Skills

    Students are able to:
    • Predict relative properties of elements using the periodic table.
    • Predict patterns in periodic trends based on the structure of the atom.
    • Predict patterns in bonding and shape based on the structure of the atom.
    • Use the periodic table to determine how elements will bond.

    Understanding

    Students understand that:
    • Models are based on evidence to illustrate the relationships between systems or between components of a system.
    • Each atom has a charged substructure consisting of a nucleus, which is made of protons and neutrons, surrounded by electrons.
    • The periodic table arranges elements into periods/ rows by the number of protons in the atom's nucleus.
    • Elements with similar properties are placed into groups/ families/ columns based on the repeating pattern of valence electrons in their atoms.
    • Attraction and repulsion between electrical charges at the atomic scale explain the structure, properites, and transformations of matter, as well as the contact forces between material objects.
    • The attraction and repulsion of charged particles in the atom creates patterns of properties of elements.
    • The arrangement of valence electrons in an atom also creates patterns of properties of elements.
    • Elements form bonds based upon their valence electron arrangement.
    • Chemical compounds are named based upon the type of bonds formed by their constituent atoms/ ions.
    • Different patterns may be observed at the atomic/ molecular level and the macroscopic level.

    Scientific and Engineering Practices

    Developing and Using Models; Analyzing and Interpreting Data

    Crosscutting Concepts

    Patterns; Systems and System Models; Structure and Function
    Science (2015) Grade(s): 09-12 - Chemistry

    SC15.CHM.3b

    Develop and use models (e.g., Lewis dot, 3-D ball-and-stick, space-filling, valence-shell electron-pair repulsion [VSEPR]) to predict the type of bonding and shape of simple compounds.

    Link to Resource

    CR Resource Type

    Interactive/Game

    Resource Provider

    PhET
    Accessibility
    License

    License Type

    Attribution
    ALSDE LOGO