Problem 1) The progress of human civilization went through three ages in the following sequence: the stone age, the bronze age, and the iron age respectively, reflecting the tools used by man. Explain why the progress materialized in that particular sequence.
Problem 2) Ceramics are hard, are chemical inert ,and are therefore not subject to corrosion Can we use them to build structures or structural components? Explain why.
Problem 3) Some plastics do not melt at a constant temperature ,but within a range of temperatures, while others do not melt at all but char and burn. Why?
Problem 4) When we hammer ductile metals at room temperature, they become harder and begin to lose their ductility. Explain why.
Problem 5) Can we change the crystal lattice of iron? How?