Substances and atomic structure - Particles and their behavior, periodic table organization, atomic bonding and structure. Chemical reactions and calculations - Ratios in reactions, mole concept, rates of reaction, equilibrium, redox reactions. Energy and electricity in chemistry - Energy changes in reactions, electricity’s role in chemical processes. Acids, bases, and salts - Properties and reactions of acids and bases, salt preparation methods. Metals, non-metals, and gases - Identification of gases and ions, properties of metals and non-metals, role of water and air. Organic chemistry and polymers - Families of organic compounds, fuels, synthetic and natural polymers.