This lecture focuses on the exercises related to metals and alloys, specifically addressing the production and recycling of iron and aluminum. It begins with a true or false exercise regarding global aluminum resources and cobalt reserves, highlighting the impact of geopolitical factors on resource availability. The instructor presents calculations involving the density and composition of charcoal and wood in the production of cast iron and steel, emphasizing the energy requirements for these processes. The lecture also discusses the energy consumption in selective laser melting of aluminum, comparing it to traditional production methods. The importance of recycling iron is underscored, with calculations showing the cost-effectiveness of recycling compared to primary production. Additionally, the lecture explores the thermodynamic aspects of magnesium oxidation, providing insights into free energy changes during reactions. Overall, the lecture integrates practical exercises with theoretical concepts, illustrating the complexities of material production and sustainability in metallurgy.