The Matter — The Periodic Table of Elements

About this lesson

This lesson focuses on the periodic table of elements. It begins by describing historical attempts to classify elements, specifically mentioning Dmitri Mendeleev's table, which arranged elements in ascending order of atomic mass, and Moseley's table, which arranged them by atomic number. The lesson then introduces the modern periodic table, which consists of 7 periods and 18 groups, and explains how an element's location (period and group) relates to its electron configuration, including the number of energy levels and valence electrons. It also covers the classification of elements into blocks (s, p, d, f), types (metals, nonmetals, metalloids), and specific groups such as alkali metals, alkaline earth metals, halogens, and noble gases. The lesson discusses valency, Lewis structures, and trends in atomic radius, melting point, and boiling point within groups. Activities and evaluation questions are included to help students apply these concepts.