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Lesson 2 - Basic Definitions and Concepts

Student Performance Objectives
1. Define each of the following basic terms: element, atom, compound, molecule, matter
(substance), and density.
2. Define proton, neutron, electron, atomic number, atomic mass, and Bohr model of an atom.
3. Define valence electrons, octet rule, and electron dot diagram.
4. Draw the Bohr model and electron dot diagram for any atom from atomic number 1 - 20
given its atomic number and atomic mass.

Lesson Outline
A. Definitions
    1. Elements - the simplest substances in nature.
2. Atoms - the smallest units of the elements.
3. Compounds - substances composed of two or more elements.
    4. Molecules - the smallest units of compounds.
    5. Matter - define and distinguish from energy.
    6. Density - the amount of matter (measured as mass) per unit of volume.
B. DEMONSTRATION: the point is to physically demonstrate the definition of matter which
    is "anything that occupies space and has mass," and to clarify the meaning of density.
    An empty, small box is measured by a student with a metric ruler to obtain its dimensions
    which are given to the class. The class calculates the box's volume in cubic centimeters.
    The box is then weighed, in grams, by a different student using a triple beam balance and
    the class calculates the box's density in g/cc. Then some weights are placed inside the
    box and the box is again weighed. The box's new density is calculated.
C. Related to the human body
    1. Minerals
D. Atomic structure
    2. Major minerals
    3. Trace minerals 

    1. Bohr model and concept of atomic number.
    2. Nucleus containing protons and neutrons and concept of atomic mass
    3. Electron cloud and valance electrons
    4. Octet rule (except related to hydrogen) for filling atomic energy levels
    5. Illustrate structural diagrams for the common elements of human body - sodium and
        chloride. Students must be able to diagram atoms from atomic number 1 through 20.
    6. Electron dot diagrams to illustrate the valence electrons on an atom.

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