STANDARD 5.6 (Chemistry) — All students will gain an understanding of the structure and behavior of matter.

DESCRIPTIVE STATEMENT: Exploring the nature of matter and energy is essential to an understanding of the physical universe. This standard leads students from their experiences with the states and properties of matter, to the development of models of the atom and the underlying principles of chemistry.

CUMULATIVE PROGRESS INDICATORS: Building upon knowledge and skills gained in the preceding grades, by the end of Grade 12, students will...

1. Structure and Properties of Matter
   1. Know that atoms are made of a positive nucleus surrounded by negative electrons and that the nucleus, a tiny fraction of the volume of an atom, is composed of protons and neutrons, each almost 2,000 times more massive than an electron.
   2. Know that the number of protons in the nucleus defines the element.
   3. Know that an atom’s electron arrangement, particularly the outermost electrons, determines how the atom can interact with other atoms.
   4. Explain that atoms form bonds (ionic and covalent) with other atoms by transferring or sharing electrons.
   5. Explain how the Periodic Table of Elements reflects the relationship between the properties of elements and their atomic structure.
   6. Know that many biological, chemical and physical phenomena can be explained by changes in the arrangement and motion of atoms and molecules.
   7. Recognize that the properties of matter are related to the structure and arrangement of their molecules and atoms, such as in metallic and nonmetallic crystals and carbon compounds.
   8. Know that different levels of energy are associated with different arrangements of electrons.
2. Chemical Reactions
   1. Explain that the rate of reactions among atoms and molecules depends on how often they encounter one another and that the rate is affected by nature of reactants, concentration, pressure, temperature, and the presence of a catalyst.
   2. Show that some changes in chemical bonds require a net input or net release of energy.