The book is available for students to consider the chemistry of thirty-seven elements that make up, according to modern ideas, the III group of the periodic system of D. I. Mendeleev, including such important elements as boron, aluminum, uranium. It is described in detail and fascinatingly about lanthanides and actinides, the role of which in the chemical industry, metallurgy, nuclear energy, agriculture, medicine is increasing in connection with scientific and technological progress. The material collected in the book will interest students and captivate them in the world of chemistry.