Technetium

Introduction

'Technetium is a radioactive element and has various radioactive isotopes as well which are thoroughly unstable except for the completely ionized state of 97Tc. This substance is synthetically produced in laboratories for various industrial applications. Naturally, this substance is mostly obtained from molybdenum ores. It is the lightest element containing all radioactive isotopes.

What is technetium?

Technetium is a chemical substance that is radioactive in nature. The atomic number of this element is 43 and is represented using the symbol Tc. All the isotopes of this element are known to be radioactive out of which technetium-99 is the most important of all and can be critically life-threatening if it is not handled with proper precautions. Only the97Tc is stable when it is in an ionized form. This substance can be obtained from nature and it can be prepared using an industrial setup. It has a silver-grey appearance that tarnishes down slowly as it comes in contact with the moisture present in the air.

This radioactive element is used in different industrial processes and is primarily utilised as a corrosion inhibitor for steel. It is found in group 7 and block d of the periodic table. This substance is not known to have any application for biological processes and is not found in the human body.

Properties of technetium

There are several properties associated with technetium some of the physical and chemical properties of this element are mentioned below −

Figure 2 − Technetium

Physical properties

• A silvery grey radioactive metal looks like platinum.

• In the form of pure metal, it has a hexagonal crystal structure that is compactly packed.

• The NMR spectrum of nano disperse technetium of 99Tc is not split while the 99Tc-NMR of hexagonal bulk is divided into 9 satellites.

• Its metallic form is slightly paramagnetic in nature.

• Technetium is known to display the largest magnetic penetration depth below the temperature of 7.46K. At this temperature, the substance exists in a pure form and is metallic in nature and the single crystal technetium alters into niobium.

• It exists in a solid form at room temperature. Characteristic wavelengths of 363nm, 403.1nm, 426.2nm, 429nm and 485.3nm are liberated by atomic technetium.

Chemical properties

• The density of technetium is 11.5g/cc. This element begins to melt at 2430K and it boils at 4535K.

• The atomic radius of this element is 136pm.

• The covalent radius of the substance is 127pm and its ionic radius is 56.

• The fusion heat of this element is 23.8kJ/mole.

• The evaporation heat of this element is 585.

• Atomic mass of this element is 98amu. The molecular weight of technetium is +7,+5 and +4.

Isotopes of technetium

The traits of the isotopes of this element are mentioned below −

• Technetium-97 exhibits a half-life of 4.21 million years.

• Half-life of technetium-98 is 4.2 million years.

• Technetium-99 has a half-life of 211,100 years

• This element has thirty other radioactive isotopes that have mass numbers ranging from 85 to 118.

• Technetium also possesses a vast number of nuclear isomers that possess isotopes of one or multiple excited nucleons. It has a half-life of 91 days and also exhibits excitation energy of 0.0965 MeV.

• The ionised form of technetium-97 is the most stable of all the isotopes.

• It is the lowest numbered element found in the period table that possesses radioactive isotopes.

Uses of technetium

The uses of technetium are mentioned below:

Figure 3 − Uses of technetium

• It protects the steel from getting corroded.

• This element is useful in developing photoelectric nuclear batteries.

• Technetium also helps in structuring the circulatory system.

• Technetium-99 is utilised in nuclear medicinal processes for various diagnostic tests. Primarily it helps in diagnosing bone cancer.

• This element utilised in several radiopharmaceutical processes. It is quite an effective radioactive tracer as it emits 140KeV of gamma rays and it is easily traceable.

• It is an effective catalyst for dehydrogenation of isopropyl alcohol. It radioactivity however is harmful in catalytic processes.

Occurrence of technetium

Technetium can be found in trace quantities from uranium ores. The isotope of technetium-99 can be gathered from the waste products liberated from the nuclear fuel of uranium. Nuclear activation of molybdenum-98 creates molybdenum-99 It decays by beta emission to create technetium-99m. This element can also be created by spontaneous fission of uranium ore and thorium ores.

The long half period of this element helps to stay in the environment however transportation is delayed due to the presence of organic matter found in the soil.

Conclusion

Technetium is a highly radioactive element and so are its isotopes. This element thus is quite harmful to human health. Precaution should be undertaken while handling this substance or it will lead to fatal consequences. This element utilised in various pharmaceutical processes. It used in several other industrial processes it is the lightest of all the elements that have radioactive isotopes and all of them are unstable.

FAQs

1. How is technetium produced by industrial processes?

Technetium is obtained by clashing molybdenum 98Mo with neutrons to create molybdenum 99Mo. It helps in creating technetium-99m. The resulting molybdenum 99Mo decays to a metastable state after 66 hours of its half-life. Molybdenum 99Mo can be differentiated from other fission products that help in creating technetium-99m.

2. What are the harmful effects of technetium?

Technetium is critically harmful to the health of an individual since this product is highly radioactive. This substance is utilised in pharmaceutical processes but prolonged exposure enhances the risk of cancer in an individual. This substance deposits in the gastrointestinal tract.

3. Why is technetium considered to be a synthetic product?

Technetium is considered a synthetic product since most of the isotopes of technetium contain an extra amount of neutrons. This substance is also artificially created in industries.