Transition metals-they often exhibit several common oxidation states.

Scandium- is mainly used for research purposes.

Yttrium- is often used as an additive in alloys.

Titanium- is as strong as steel but much less dense. It is therefore important as an alloying agent with many metals.

Zirconium- does not absorb neutrons, making it an ideal material for use in nuclear power stations.

Hafnium has a good thermal absorption cross-section for neutrons, so is used in control rods in nuclear reactors. 

Rutherfordium- at present, it is only used in research.

vanadium- produced is used as a steel additive.

Niobium- is used in alloys including stainless steel.

Tantalum- causes no immune response in mammals, so has found wide use in the making of surgical implants.

Dubinum- at present, it is only used in research.

Chromium- is used to harden steel.

Molybdenum- has a very high melting point so it is produced and sold as a grey powder.

Tungsten- was used extensively for the filaments of old-style incandescent light bulbs.

Seaborgium- at present, it is only used in research.

Manganese- is too brittle to be of much use as a pure metal. It is mainly used in alloys, such as steel. 

Technetium- is widely used for medical diagnostic studies.

Rhenium- is used as an additive to tungsten- and molybdenum-based alloys to give useful properties. These alloys are used for oven filaments and x-ray machines.

Bohrium- at present, bohrium is of research interest only.

Iron- is used to manufacture steel.