A STUDENT SHOULD KNOW THAT:

A. AN ATOM CONSISTS OF A NUCLEUS SURROUNDED BY ELECTRONS, AND THE ARRANGEMENT
     OF THE ELECTRONS DETERMINES THE CHEMICAL BEHAVIOR OF EACH ELEMENT.

1. Atoms differ in the number of protons in the nucleus and in the electrons surrounding the nucleus.
2. The arrangement of the electrons of an atom determines the chemical behavior of an atom.
3. In a neutral atom, the total number of electrons is equal to the number of protons in the nucleus.

B. THE NUCLEUS CONSISTS OF PROTONS AND NEUTRONS, AND WHILE EACH ATOM OF A GIVEN 
     ELEMENT HAS THE SAME NUMBER OF PROTONS, THE NUMBER OF NEUTRONS MAY VARY.

1. The mass of an atom is concentrated almost entirely in the nucleus.
2. Isotopes are forms of an element with differing numbers of neutrons that give the isotopes different mass.

C. ATOMS CAN FORM BONDS WITH OTHER ATOMS BY TRANSFERRING OR
     SHARING ELECTRONS.

1. Atoms may combine to form compounds and/or molecules.
2. Atoms may transfer electrons to another atom or atoms may share electrons equally or unequally between them to form a compound.
3. Elements form compounds to gain stability.
4. Chemical symbols and formulae can be used to symbolically represent how atoms combine to form compounds and molecules.

D. THERE ARE DIFFERENT KINDS OF CHEMICAL REACTIONS.

1. Chemical reactions depend on collisions between the reacting particles to form new combinations of atoms.
2. Chemical equations symbolically represent chemical reactions.

E. REACTION RATES ARE AFFECTED BY FACTORS SUCH AS CONCENTRATION, PRESSURE,
    TEMPERATURE, AND/OR THE PRESENCE OF A CATALYST.

F. ELEMENTS CAN BE ORGANIZED, BASED UPON CHEMICAL AND PHYSICAL PROPERTIES, INTO
    THE PERIODIC TABLE.

1. The atomic number is he basis of the arrangement in the present form of the periodic table.  For example, elements can be grouped as metals, nonmetals, and noble gases.
2. The properties of the elements depend on the structure of the atom and vary with the atomic number in a systematic way.

TO UNDERSTAND THE CONCEPTS OUTLINED ABOVE, A STUDENT SHOULD BE ABLE TO:

• Use models to explain the structure and behavior of atoms.
• Use models to explain the formation of molecules.
• Identify, given a balanced equation, the type of chemical reaction shown.
• Identify and predict, given a description of the behavior of a reaction, a condition which will affect the rate of the reaction.
• Describe, given a periodic table of the elements, a specific element's chemical and physical properties.