Understand that all substances are comprised of matter and energy.

• Contrast matter and energy.
• Summarize the difference between potential and kinetic energy.
• State why energy is necessary for life.

Recognize the basic structure of atoms.

• Discriminate between atoms and elements; molecules and compounds.
• Describe the information found in the periodic table of the elements.
• Describe how isotopes differ from one another.
• Differentiate among atomic weight, atomic number, atomic mass, and mass number.
• Explain how atoms stick together to form compounds.
• Contrast chemical bonds and hydrogen bonds.
• Describe the differences among liquids, solids, and gases.

Describe the chemical nature of water.

• Understand the roles water plays in maintaining life.
• Differentiate among solution, solvent, and solute.

Recognize how compounds may be broken down and reconnected in different ways.

• List the five types of chemical reactions associated with all living things.
• Explain the difference between reactants and products.
• Identify compounds that are acids, bases, or salts.
• Work with the pH scale.