This chemistry lesson document discusses classifying elements and compounds. It provides learning competencies around recognizing that substances can be classified as elements or compounds. The lesson involves students working in groups to identify common elements by name and symbol. Students then identify the elements in example compounds such as potassium nitrate, carbon monoxide, sodium chloride, and nitrous oxide. The lesson concludes with an activity where students build example compounds from given elements such as lithium oxide, potassium bromide, and water.