Scope, Sequence, and Coordination

A Framework for High School Science Education

Based on the National Science Education Standards

Physical Properties of Matter

Molecules: Their Structure, Interactions, and Physical Properties
The physical properties of compounds reflect the nature of the interactions among their molecules. These interactions are determined by the structure of the molecule, including the constituent atoms and the distances and angles between them.

Further Description:

Substances can be distinguished by a wide variety of properties, such as physical state at room temperature, hardness, electrical conductivity, melting point, boiling point, solubility, malleability, ductility, and density.

The properties of compounds reflect the nature of the interactions among the molecules, atoms, or ions, which are determined by the structure of the molecules. These interactions include van der Waal’s forces, dipole-dipole interactions, hydrogen bonding, and network bonding. Shapes of molecules can be predicted from the electronic structure of the atoms using Lewis dot diagrams of compounds.

Concepts Needed:

Grade 9

States of matter, electrical conductivity, melting point, boiling point, solubility, malleability, ductility, density

Grade 10

Metallic crystal, ionic crystal, covalent compound, ionic compound, chemical stability, electrostatic attraction

Grade 11

Solubility, miscibility, polarity, hydrogen bonding, network bonding

Grade 12

Van der Waal=s forces, London forces, dipole-dipole interaction

Empirical Laws or Observed Relationships:

None suggested

Theories or Models:

Hydrogen bonding, network structure, electronic structure, Lewis electron-pair bond model, ionic network, intermolecular force theories (van der Waal, London, dipole-dipole)

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