Symbol Hf
Atomic Number 72
Atomic Mass 178.49 g.mol 1
Discovered by George Charles de Hevesy and Dirk Coster  in 1923

Chemical Properties of Hafnium

Group 4 Melting point 2233°C, 4051°F, 2506 K
Period 6 Boiling point 4600°C, 8312°F, 4873 K
Block d Density (g cm3) 13.3
Atomic number 72 Relative atomic mass 178.49
State at 20°C Solid Key isotopes 177Hf, 178Hf, 180Hf
Electron configuration [Xe] 4f145d26s2 CAS number 7440-58-6
ChemSpider ID 22422 ChemSpider is a free chemical structure database

What is Hafnium?

  • Hafnium is a tetravalent transition metal with atomic number 72 and represented with the symbol Hf in the Periodic Table.
  • Hf was named after the city in which it was discovered in, Copenhagen whose Latin name is Hafnia.

Physical properties of Hafnium

  • Hafnium is a shiny and silvery metal exhibiting ductile features.
  • It is usually resistant to corrosion and exhibits similar chemical properties to that of zirconium. This similarity is because of the presence of valence electrons which are same and that of the same group.
  • The impurities present in the zirconium highly affects the hafnium metal. Hence both of them are considered to be the most inseparable.
  • When reacted with water, a thin film of a protective layer is formed on the metal which shows the occurrence of corrosion.
  • There is no effect of acids over the metal, but still, when ignited in the presence of oxygen, the metal produces oxides. This metal is highly resistant to some of the concentrated alkalis.
  • Around 5.8 ppm of the upper layer of the earth’s crust constitutes of this metal. This element does not exist freely in the environment.

Applications and effects of Hafnium

  • Hafnium has a unique property of capturing neutrons. Hence it is used in the control rods of reactors as well as nuclear submarines
  • Its compounds are used in the ceramic and alloy industries as they have higher melting points.
  • It is widely utilized in the microprocessors as they are involved in the reduction of leakage current.
  • It is also used in incandescent and gas-filled lamps.
  • This metal serves as electrode in the process of plasma cutting as it gives out electrons

Health effects of Hafnium

  • Not hafnium, but the compounds of this metal are said to be toxic in nature. These compounds are said to possess fire hazards and explosive properties.
  • An overexposure of this can cause several health disorders such as developing irritation in eyes, mucous membranes, and skin. There are not many environmental impacts shown by hafnium except few of them occurring very rarely.

Practise This Question

Terylene can be drawn into very fine fibres that can be woven like any other yarn. True/False