The term "d-Block" refers to a specific section of the periodic table that includes transition metals. These elements are found in groups 3 to 12 and are characterized by their ability to form variable oxidation states and complex ions. Common examples of d-block elements include iron, copper, and gold. They are known for their metallic properties, such as conductivity and malleability. D-block elements play crucial roles in various industrial applications and biological processes. For instance, catalysts made from d-block metals are essential in chemical reactions, while some, like zinc and cobalt, are vital for human health. Their unique properties make them important in fields ranging from electronics to medicine.