What is Technetium Definition Properties Isotopes and Uses
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 in Chemistry Structure Properties and Applications
1. What is technetium?
Technetium is a synthetic radioactive transition metal with atomic number 43 and symbol Tc. It belongs to Group 7 of the periodic table and was the first element artificially produced. Key facts about technetium include:
- Atomic number: 43
- Electron configuration: [Kr] 4d5 5s2
- All isotopes are radioactive
- Commonly used in nuclear medicine
Technetium does not occur naturally in large amounts and is mainly obtained from nuclear reactors.
2. Why is technetium radioactive?
Technetium is radioactive because none of its isotopes are stable, meaning their nuclei are inherently unstable and undergo radioactive decay. The instability arises from an unfavorable neutron-to-proton ratio in all Tc isotopes. As a result:
- Technetium isotopes undergo beta (β) decay.
- They transform into more stable elements such as ruthenium (Ru).
- For example, Tc-99 decays to Ru-99 by emitting a β− particle.
This radioactive nature makes technetium valuable in tracer and diagnostic applications.
3. What is technetium-99m used for?
Technetium-99m (Tc-99m) is primarily used as a radioactive tracer in medical imaging. It emits gamma radiation suitable for detection by gamma cameras without causing excessive tissue damage.
- Half-life: about 6 hours
- Decay mode: isomeric transition to Tc-99
- Used in bone scans, heart imaging, and kidney function tests
Its short half-life and pure gamma emission make Tc-99m ideal for diagnostic nuclear medicine.
4. What is the electron configuration of technetium?
The electron configuration of technetium (Tc) is [Kr] 4d5 5s2. This configuration reflects its position in Group 7 of the d-block.
- Core configuration: [Kr]
- d-electrons: 4d5
- s-electrons: 5s2
The half-filled 4d subshell contributes to technetium’s multiple oxidation states and transition metal chemistry.
5. What are the common oxidation states of technetium?
Technetium commonly exhibits oxidation states of +7, +6, +4, and +2, with +7 being the most stable. These oxidation states are typical of Group 7 transition metals.
- +7: Found in the pertechnetate ion TcO4−
- +4: Present in compounds like TcO2
- Lower states such as +2 occur in coordination complexes
The wide range of oxidation states is due to the involvement of 4d and 5s electrons in bonding.
6. What is the pertechnetate ion?
The pertechnetate ion is the polyatomic ion TcO4−, in which technetium is in the +7 oxidation state. It is analogous to permanganate (MnO4−).
- Geometry: tetrahedral
- Technetium oxidation number: +7
- Common in medical radiopharmaceuticals
Pertechnetate salts, such as sodium pertechnetate (NaTcO4), are widely used in nuclear medicine.
7. How is technetium produced?
Technetium is mainly produced as a fission product of uranium-235 in nuclear reactors. It forms during the nuclear fission process.
- Nuclear reaction example: 235U + n → fission fragments + 2–3n
- One of the fission fragments is Tc-99
- Tc-99m is obtained from a molybdenum-99 generator
The decay process in generators is: 99Mo → 99mTc + β−, allowing controlled medical use.
8. How does technetium-99m decay?
Technetium-99m decays by isomeric transition to technetium-99, emitting a gamma (γ) photon. This process does not change the atomic number.
- Decay equation: 99mTc → 99Tc + γ
- Half-life: approximately 6 hours
- No beta particle is emitted in this step
The emitted gamma radiation is detected in diagnostic imaging procedures.
9. What are the chemical properties of technetium?
Technetium is a silvery-gray transition metal that forms oxides, halides, and coordination compounds in multiple oxidation states. Its chemistry resembles manganese and rhenium.
- Forms oxide TcO2 and pertechnetate TcO4−
- Reacts with oxygen at high temperature to form oxides
- Forms complexes with ligands such as NH3 and Cl−
Because it is radioactive, its chemistry is often studied using tracer techniques.
10. Why is technetium important in chemistry and medicine?
Technetium is important because it is widely used in diagnostic nuclear medicine and demonstrates key principles of transition metal chemistry. Its isotope Tc-99m is the most used medical radioisotope worldwide.
- Used in millions of medical imaging procedures annually
- Demonstrates variable oxidation states and coordination chemistry
- Plays a role in studies of radioactive decay and nuclear chemistry
Its combination of suitable half-life, gamma emission, and chemical versatility makes technetium uniquely valuable.
