Technetium

**Atomic Weight: 98**

 * Technetium** the lowest atomic number element without any stable isotopes; every form of it is radioactive. Nearly all technetium is produced synthetically and only minute amounts are found in nature. Naturally occurring technetium occurs as a spontaneous fission product in uranium ore or by neutron capture in molybdenum ores. The chemical properties of this silvery gray, crystalline transition metal are intermediate between rhenium and manganese.

Many of technetium's properties were predicted by Dmitri Medeleev before the element was discovered. Mendeleev noted a gap in his periodic table and gave the undiscovered element the provisional name ekamanganese. In 1937 technetium (specifically the technetium-97 isotope) became the first predominantly artificial element to be produced. Its short-lived gamma ray-emitting nuclear isomer - technetiu-99m - is used in nuclear medicine for a wide variety of diagnostic tests. -99 is used as a gamma ray-free source of beta particles. Long-lived technetium isotopes produced commercially are by-products of fission of uranium-235 in nuclear reactors and are extracted from nuclear fuel rods. Because no isotope of technetium has a half-life longer than 4.2 million years, its detection in red giants in 1952, which are billions of years old, helped bolster the theory that stars can produce heavier elements.
 * __History__**



Harmful effects: Technetium is harmful due to its radioactivity. Characteristics: Technetium is a rare, silver-gray metal that tarnishes slowly in moist air. In powder form, it burns in oxygen to the heptoxide (Tc2O7). Technetium dissolves in nitric acid and concentrated sulfuric acid, but is not soluble in hydrochloric acid of any strength. Is an excellent superconductor at temperatures of 11 K and below. Technetium and promethium are notable among the light elements because they both have no stable isotopes.
 * __ Effects __**

Uses of Technetium
Technetium-99m is a metastable isotope with a half-life of six hours. Technetium-99m emits gamma rays and low energy electrons, forming technetium-99 (half-life 211 000 years). The gamma rays can be photographed using a gamma camera, and technetium-99m is used in 80 to 90 percent of all diagnostic procedures that use radioactive elements. Technetium-95, with a half-life of 61 days, is used as a radioactive tracer. Technetium-99, has a very long half-life (2.11 X 105 years) and decays almost entirely by beta decay with no gamma rays. It is used as for equipment calibration. In small concentrations the pertechnetate ion (TcO 4-) can protect carbon steels and iron from corrosion. This use is limited to closed systems due to its radioactivity.
 * ammonium pertechnate, NH4TcO4, is a specialist corrosion inhibitor for steel. Mild carbon steels are protected by 5 ppm of KTcO4 in aerated distilled water at temperatures up to 250°C. This corrosion protection is limited to closed systems, since technetium is radioactive
 * superconductor at 11 K and below
 * medical imaging agents
 * 95Tc is used for tracer work (radioactive tracers)


 * Name:** Technetium **Symbol:** Tc **Atomic Number:** 43 **Atomic Mass:** (98.0) amu **Melting Point:** 2200.0 °C (2473.15 K, 3992.0 °F) **Boiling Point:** 4877.0 °C (5150.15 K, 8810.6 °F) **Number of Protons/Electrons:** 43 **Number of Neutrons:** 55 **Classification:** Transition Metal **Crystal Structure:** Hexagonal **Density @ 293 K:** 11.5 g/cm3 **Color:** Unknown

Atomic Structure

 * [[image:http://www.chemicalelements.com/bohr/b0043.gif width="300" height="299"]] ||  || **Number of Energy Levels:** 5
 * First Energy Level:** **Second Energy Level:** **Third Energy Level:** **Fourth Energy Level:** **Fifth Energy Level:** ||

Isotopes

 * ** Isotope ** || ** Half Life ** ||
 * Tc-95 || 20.0 hours ||
 * Tc-95m || 61.0 days ||
 * Tc-96 || 4.28 days ||
 * Tc-96m || 51.5 minutes ||
 * Tc-97 || 2600000 years ||
 * Tc-97m || 90.0 days ||
 * Tc-98 || 4200000 years ||
 * Tc-99 || 2.13E5 years ||
 * Tc-99m || 6.0 hours ||
 * Tc-100 || 14.2 minutes ||

Facts
Technetium can be found in nature such as the Earth's crust, another example of where to find it would be within radioactive metals.
 * Date of Discovery:** 1937 **Discoverer:** Carlo Perrier **Name Origin:** From the Greek word //technêtos// (artificial) **Uses:** Tc-99m is used for radioactive tracing in medicine **Obtained From:** Man-made