Chemistry: Basic Principles of the Structure of Matter and Energy Concepts

This course (designed for grade 11 or 12) builds on the content learned in the Introduction to Chemistry course and further develops students’ understanding of the chemical nature of matter; properties and reactions of matter; related energy concepts; and applications of this knowledge to everyday life.

Within the course, there are four main themes from which to develop standards-based learning cycle lessons:

• Nature of matter and atomic structure
• Nuclear chemistry
• Chemical bonding
• Equilibrium

Nature of Matter and Atomic Structure

• Atomic structure and the interactions of matter can be represented symbolically and mathematically. One example is the notion that electrons possess both wave and particle properties—a modern view based on a mathematical understanding of the atom and the relationship between matter and energy.
• The historical contributions of Dalton, Thomson, Rutherford, Planck, Einstein, Bohr, Schrodinger, Pauli, and Heisenberg have helped to build current understandings of atomic structure.
• Each electron has a unique electron configuration (Pauli exclusion principle). Understanding how electron configurations are assigned and how these configurations translate into orbital and electron dot notation provides an increased awareness of why certain elements tend to gain/lose/share electrons when forming chemical bonds.

Nuclear Chemistry

• Isotopes are different forms of the same element. If an isotope has an unstable nucleus or if it is produced artificially, it is radioactive. In some cases, all isotopes of an element are radioactive. Uranium is one such element.
• Radioactive decay occurs as unstable nuclei emit radiation in order to become more stable. This radiation can take the form of alpha particles, beta particles, gamma particles, or neutron rays. Radioactive decay is a continuous natural process.
• Radioactive elements have a variety of applications in medicine, power generation, warfare, and radiometric dating.

Chemical Bonding

• Molecular shape is a result of the position of paired and unpaired electrons. By taking into account shape and bond type, the degree of polarity of molecules can be described and compared.
• Differences in electronegativity values are used to predict relative bond strengths and types. A general rule of thumb is that the larger the electronegativity difference, the greater the polarity of the bond. Bonds can be categorized as ionic, polar covalent, nonpolar covalent, or metallic.
• Molecular polarity affects properties of molecules such as boiling point, freezing point, and solubility and determines how molecules will interact.
• The study of organic chemistry builds on the concepts of bonding, bridges the gap between chemistry and biology, and provides a framework for understanding carbon-based compounds. Organic chemistry is important in our daily lives through pharmaceuticals, polymers, biological molecules, and soaps.

Equilibrium

• Chemical equilibrium is the state in which the concentration of reactants and products remains constant provided no additional reactants are added to the system. Forward and reverse reactions continue, but the concentration of the reactants and products remains unchanged. It can be mathematically determined using an equilibrium constant (K_eq). One example is comparing acid and base strength using K_a and K_b values.
• Stresses (addition of a catalyst or changes in temperature, pressure, or concentrations of either reactants or products) can be applied to reactions that have established equilibrium, causing a shift in the reaction until a new equilibrium is established. This is useful if trying to force the reaction to produce more product.
• Chemical equilibrium plays an important role in many industrial processes. The synthesis of ammonia is an important example. During the reaction, high temperatures and pressures are utilized to shift the reaction toward completion rather than equilibrium.