Transition elements are metallic elements that have incomplete d or f shells in the neutral or cationic states. They are called also transition metals and make up 56 of the 103 elements. These transition metals are classi
t of 3d elements from Sc to Cu, 4d elements from Y to Ag, and 5d elements from Hf to Au, and f-block metals, which consist of lanthanoid elements from La to Lu and actinoid elements from Ac to Lr. Although Sc
ties are similar to those of lanthanoids. The chemistry of d-block and f-block elements differs considerably. This chapter describes the properties and chemistry of mainly d-block transition metals.