Tc Element
Technetium, with the symbol Tc and the atomic number 43, is a chemical element. Technetium element is the lightest element whose isotopes are all radioactive, none of which is stable other than 97Tc's completely ionized state. As a synthetic element, almost all usable technetium is made. Naturally occurring technetium, the most common source or result of neutron capture in molybdenum ores, or is a spontaneous fission product in uranium ore and thorium ore.
Tc Periodic Table
It belongs to group 7 and period 5. It is a d block element. It is solid at 20C.
Technetium atomic number is 43
Tc Electronic configuration- [Kr] 4d5 5s2
Melting point- 2157°C, 3915°F, 2430 K
Boiling point- 4262°C, 7704°F, 4535 K
Density - 11
Relative atomic mass- 98
Physical Properties of Technetium
Technetium, commonly obtained as a gray powder, is a silvery-gray radioactive metal with an appearance identical to platinum. The pure metal's crystal structure is hexagonal close-packed. Atomic technetium has characteristic wavelength emission lines of 363.3 nm, 403.1 nm, 426.2 nm, 429.7 nm, and 485.3 nm respectively.
The metal type is slightly paramagnetic, indicating that its magnetic dipoles interact with external magnetic fields, but once the field is removed, they will assume random orientations. At temperatures below 7.46 K, pure, metallic, single-crystal technetium becomes a type-II superconductor. Technetium has a very high magnetic penetration depth below this temperature, greater than any other element, except for niobium.
Chemical Properties of Technetium
Its chemical properties are between those two elements, as predicted by the periodic law. Of the two, technetium, especially in its chemical inertness and propensity to form covalent bonds, closely resembles rhenium.[26] Unlike manganese, technetium does not easily form cations (ions with a net positive charge). Technetium shows nine states of oxidation from -1 to +7, the most common being +4, +5, and +7. Technetium dissolves in aqua regia, nitric acid, and concentrated sulfuric acid, but is not soluble in any concentration of hydrochloric acid.
Metallic technetium steadily tarnishes in moist air and burns in oxygen in powder form.
Technetium Uses
Used as a catalyst equivalent to the use of rhenium and palladium.
Protect steel from corrosion.
In the development of photoelectric nuclear batteries, some compounds are helpful.
For mapping the circulatory system and any illnesses, the metal could be used.
Proposedly, optoelectric nuclear batteries may be used.
Did You Know?
As it is a radioactive metal, it is dangerous and life-threatening.
The 99Tc compound is extremely contaminated and life-threatening in nature.
When handling the chemical, one must use a protective glove box.
FAQs on Technetium
1. What are the main uses of technetium in medicine and industry?
Technetium's primary use is in nuclear medicine. Its metastable isotope, technetium-99m (Tc-99m), emits gamma rays and is widely used for diagnostic imaging to map the circulatory system, organs, and detect diseases. In industrial applications, technetium is an exceptional corrosion inhibitor for steel, providing excellent protection even in very small amounts.
2. What are the key physical and chemical properties of technetium?
Technetium (Tc) is a silvery-gray, radioactive metal with properties similar to platinum. Here are some of its key characteristics:
- Atomic Number: 43
- Electronic Configuration: [Kr] 4d⁵ 5s²
- Physical State: Solid at 20°C with a hexagonal close-packed crystal structure.
- Chemical Properties: It is slightly paramagnetic and shows multiple oxidation states, with +4, +5, and +7 being the most common. It dissolves in nitric acid and concentrated sulfuric acid but not in hydrochloric acid.
3. How is technetium produced, given it was the first man-made element?
Technetium was the first element to be artificially produced. Since all its isotopes are radioactive and have decayed over Earth's history, it is primarily man-made. The most common method of production is through the neutron bombardment of molybdenum-98 in nuclear reactors. It can also be extracted as a product of the spontaneous fission of uranium-235.
4. Is technetium hazardous to handle?
Yes, all isotopes of technetium are radioactive and must be handled with care. The primary hazard comes from the inhalation of technetium dust, as radioactive contamination in the lungs poses a significant cancer risk. Therefore, handling technetium, especially in powdered form, requires specialised equipment like a protective glove box.
5. Why is technetium, with atomic number 43, entirely radioactive while many heavier elements are stable?
Technetium's instability is a notable exception in the periodic table, often explained by nuclear physics principles. As an element with an odd number of protons (43), it struggles to achieve a stable neutron-to-proton ratio. None of its isotopic configurations fall within the 'valley of nuclear stability.' This makes every isotope of technetium, regardless of its neutron count, prone to radioactive decay, unlike neighboring elements or even much heavier elements like lead (atomic number 82).
6. Why is naturally occurring technetium so extremely rare on Earth?
Naturally occurring technetium is rare because its most stable isotope, technetium-98, has a half-life of about 4.2 million years. This is significantly shorter than the age of the Earth (approx. 4.5 billion years). As a result, any primordial technetium that might have existed when the Earth formed has long since decayed into other elements. The trace amounts found today are continuously produced from the spontaneous fission of uranium in ores.
7. What makes the technetium-99m isotope so uniquely suited for medical imaging?
The technetium-99m (metastable) isotope is ideal for medical diagnostics for two key reasons:
- Type of Radiation: It emits low-energy gamma rays that are easily detected by imaging cameras but cause minimal damage to body tissues.
- Short Half-Life: It has a convenient half-life of approximately 6 hours. This is long enough to conduct diagnostic procedures but short enough to ensure that the radioactivity decays quickly, minimising the patient's overall radiation exposure.
8. How does technetium's electronic configuration explain its variable oxidation states?
Technetium's electronic configuration is [Kr] 4d⁵ 5s². The energies of the 4d and 5s orbitals are very close, allowing it to lose a variable number of electrons from both subshells. This ability to use both valence shells for bonding results in a wide range of possible oxidation states, from -1 to +7. The +7 oxidation state is particularly common and stable as it corresponds to losing all seven valence electrons.
9. How do the properties of technetium compare to other Group 7 elements like manganese and rhenium?
As predicted by the periodic law, technetium's properties are intermediate between manganese (Mn) and rhenium (Re). However, it more closely resembles rhenium in its chemical behavior. Like rhenium, it is relatively inert and forms stable compounds in high oxidation states (e.g., Tc₂O₇). Unlike manganese, technetium does not readily form simple cations (like Mn²⁺) and is more resistant to oxidation.
