The Periodic Table and Classification of Elements

About this lesson

This unit covers the modern periodic table, its arrangement by atomic number and the Aufbau principle, and its division into s, p, d, and f blocks. It describes the types of elements (noble gases, representative, transition, inner transition) and explains trends in atomic radius, ionization energy, electron affinity, and electronegativity across periods and down groups. It also discusses metallic and nonmetallic properties, acidic and basic oxides, and introduces oxidation numbers, oxidation-reduction reactions, and balancing redox equations using half-reactions. By the end of the unit, a student should be able to describe the periodic table, identify element types and properties from position, explain atomic radius trends, name blocks, relate electron configuration to group number, define key terms (atomic radius, ionization energy, electron affinity, electronegativity), compare electron affinity and electronegativity, locate metals and nonmetals, relate atomic radius to ionization energy and electron affinity, explain acidic/basic property trends, calculate oxidation numbers, identify redox reactions, and represent them as half-reactions.