Technetium
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Technetium
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CAS No:
7440-26-8
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Formula:
Tc
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Chemical Name:
Technetium
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Synonyms:
Technetium;Masurium;Technetium element
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CAS No:
Description
closed-packed hexagonal, a=0.2741 nm, c=0.4399nm; enthalpy of sublimation 650 kJ/mol; enthalpy of vaporization ~577 kJ/mol; enthalpy of fusion 33.29 kJ/mol; slowly tarnishes in moist air; when obtained from H2 reduction of ammonium pertechnate, has silvery gray color, and a spongy mass; resembles rhenium in chemical behavior; Debye constant 455K; used as a metallurgical tracer, in nuclear medicine, and to protect against corrosion [HAW93] [MER06] [RAR83] [CRC10]
Technetium atom is a manganese group element atom.|The first artificially produced element and a radioactive fission product of URANIUM. Technetium has the atomic symbol Tc, and atomic number 43. All technetium isotopes are radioactive. Technetium 99m (m=metastable) which is the decay product of Molybdenum 99, has a half-life of about 6 hours and is used diagnostically as a radioactive imaging agent. Technetium 99 which is a decay product of technetium 99m, has a half-life of 210,000 years.
Technetium Basic Attributes
98.00000
97.90720
231-136-0
DTXSID5075028
Close-packed hexagonal structure; isomorphous with rhodium, ruthenium, and osmium|Technetium obtained by hydrogen reduction of ammonium pertechnate is a silver-gray spongy mass which tarnishes slowly in moist air
Characteristics
0
-0.00250
11.000
2170 °C
4265ºC
Dissolves in nitric acid, aqua regia, and concentrated sulfuric acid; not soluble in hydrochloric acid of any strength
1 Pa at 2454 deg C; 10 Pa at 2725 deg C; 100 Pa at 3051 deg C; 1 kPa at 3453 deg C; 10 kPa at 3961 deg C; 100 kPa at 4621 deg C (all values are extrapolated)
Usual valences: 4 and 7; 3 less common; radioactive element, no stable nuclides; most commonly available isotope: 99; resembles rhenium in chemical behavior; burns in fluorine to form penta- and hexafluorides; combines with sulfur at room temperature to form disulfide; with carbon to form TcC (technetium carbide)|Dissolves in neutral or alkaline solution of hydrogen peroxide (H2O2) to give a solution of (TcO4)- (pertechnate ion)
Drug Information
Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR if necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on the left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Poisons A and B/|Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if needed. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 mL/kg up to 200 mL of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool ... . Cover skin burns with dry sterile dressings after decontamination ... . /Poisons A and B/|Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... . Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Treat seizures with diazepam or lorazepam ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Poisons A and B/|Basic Treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if necessary. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . Perform routine emergency care for associated injuries. For eye contamination, flush eyes immediately with water. Irrigate each eye continuously during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 ml/kg up to 200 ml of water for dilution if the patent can swallow, has a good gag reflex, and does not drool ... . Perform routine BLS care as necessary. /Radioactives I, II, and III/|Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious or is in severe respiratory distress. Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start IV administration of 0.9% saline (NS) or lactated Ringer's (LR). For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs fo fluid overload ... . Treat seizures with diazepam or lorazepam ... . Perform routine advanced life support care as needed. Use proparacaine hydrochloride to assist eye irrigation ... . /Radioactives I, II, and III/
99m, Technetium|Compounds, Technetium
Technetium Use and Manufacturing
The free metal is obtained from reactor fission products by solvent extraction followed by crystallization as ammonium pertechnetate, which is reduced with hydrogen.|Technetium was first obtained by deuteron bombardment of molybdenum, but since has been found in the fission products of uranium and plutonium.
Metallurgical tracer, cryochemistry, corrosion
resistance, nuclear medicine. Minute quantities of TcO4- ion exert remarkable inhibition of the corrosion of soft iron in neutral aqueous solution: Cartledge, J. Am. Chem. Soc. 77, 2658 (1955). Technetium is one of the few artificially produced elements that has practical industrial applications.One is that a very small amount (55-ppm) added to iron creates a corrosion-resistantalloy metal. This property is shared with many of the other transition metallic elements, but notwith other artificially produced elements that have higher atomic numbers and are radioactive.
A radioisotope of technetium is widely used in nuclear medicine. The patient is injectedwith saline solution containing Tc-99
m
(the superscript “m” means that the isotope is unstableand that its nuclei holds more energy than the regular Tc-99 nuclei into which it decays). Thismeans that the Tc-99
m
will start to emit energy and will finally decay and change to the regularnuclei of Tc-99 when injected into the patient. This energy is in the form of very penetratinggamma rays (a strong type of X-rays). The radioactive solution of Tc-99
m
may be combinedwith other elements that are absorbed by certain organs of the human body being diagnosedor treated. For instance, adding tin to the solution targets the red blood cells, whereas phosphorusin the solution concentrates the radioactive solution in heat muscles. The gamma raysare strong enough to expose an X-ray film that depicts the internal image of the organ underexamination. This procedure is safe because Tc-99
m
has a half-life of only 6.015 hours, andthe Tc-99 has a half-life of over 200,000 years. However, the radioactivity will be harmless inless than a day because the body rapidly eliminates the residual radioactive solution.
Technetium is also used as an alloy metal to produce super-strong magnets that are supercooledto near absolute zero to improve their efficiency. Powerful magnets are used in imagingequipment and possibly in future magnetic driven trains. Its radioactivity makes it useful as atracer in the production of metals and tracing flowing fluids in pipelines.
Computed Properties
Molecular Weight:96.90636
Exact Mass:96.90636
Monoisotopic Mass:96.90636
Heavy Atom Count:1
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes
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