Uranium is a weakly radioactive element discovered in 1789 by Martin Heinrich Klaproth. It is widely used to fuel nuclear power plants and to make high density penetrators. Atomic bomb is also made using Uranium.
History and Discovery
Uranium was discovered by German Chemist named Martin Heinrich Klaproth in Berlin (1789). Uranium was named by Martin after the planet Uranus which was discovered 8 years before the discovery of Uranium. It was considered a relatively rare element. But after its frequent use in making nuclear weaponry and witnessing the disaster it caused, it was decided that buying uranium deposits around the world can help in the control of nuclear weaponry production.
Uranium
| Periodic Table Classification | Group n/a Period 7 |
|---|---|
| State at 20C | Solid |
| Color | Silvery gray metallic |
| Electron Configuration | [Rn] 5f3 6d1 7s2 |
| Electron Number | 92 |
| Proton Number | 92 |
| Electron Shell | 2, 8, 18, 32, 21, 9, 2 |
| Density | 18.95 g.cm-3 at 20°C |
| Atomic number | 92 |
| Atomic Mass | 238.03 g.mol -1 |
| Electronegativity according to Pauling | 1.38 |
Occurrence
Uranium naturally occurs in soil, rock and water. It is ranked as the 51st most abundant element in earth’s crust. It is naturally formed only in supernovae. It is found in hundreds of minerals. Uraninite is the most common ore that is used to extract uranium. Some bacteria use uranium for their growth [1]. These microorganisms are widely used to clean uranium polluted water. Pure uranium is obtained through thermal decomposition of uranium halides.
Physical Characteristics
Uranium is a silvery-grey metal. And appears silvery white in refined form. Uranium is a very dense metal. It is denser than lead but less dense than tungsten and gold. Its density is 19.1 g/cm3. It is pliable and ductile element. Its atomic number is 92 and is represented by symbol U.
Chemical Characteristics
Uranium is a weakly radioactive element. It is a poor electrical conductor. Uranium is strongly electropositive and slightly paramagnetic in nature [2]. It is a highly reactive metal and is capable of reacting with all non-metal elements, along with several of their compounds. It does not reacts withnoble gases. Its reactivity increases with temperature. It is insoluble in alkalis but can be dissolved in acids. Uranium reacts with air and forms a dark layer of uranium oxide. It can also react with cold water.
Significance and Uses
- Uranium is a low-cost material and can easily be casted so it is widely used in various applications as compared to other dense metals.
- Uranium is used in making high density penetrators in military sector [3].
- Uranium is used in gyroscopic compasses and in inertial guidance systems due to its high density.
- Depleted uranium plates are used to make strong vehicle armour.
- Containers required to store, or transport radioactive materials are also made by using depleted uranium.
- Uranium is used in making counter-weights for aircraft control surfaces.
- Uranium is used as fuel in nuclear power plants.
- Depleted uranium is used as ballast for missile re-entry vehicles.
- It is used in making high energy X-rays and X-ray targets.
- It was used in making nuclear weaponry including atom bomb.
- It can be used for radiometric dating and in approximating the age of oldest igneous rocks due to its long half-life.
- Before the discovery of radioactivity, it was also used abundantly in making inexpensive pottery glazes, in manufacturing dyes for leather and wood, in toners used for photographic purposes, in lamp filaments for stage lighting etc. After its discovery as, radioactive element it was put to other, more practical usage.
Health effects
Uranium is weakly radioactive element and is not very dangerous because of its radioactivity. It is a toxic metal and some compounds of uranium like uranium oxide are poisonous. If it is inhaled, it can cause lung cancer. Finely grained uranium is dangerous as it is pyrophoric, undergoes spontaneous ignition. Exposure to uranium in large quantity or its radioactive decay products, especially radon, have substantial health damage. Uranium was used in atomic bomb which was detonated in World-war II on Japan and caused hundreds of thousands of civilian casualties.
Isotopes of Uranium
Uranium-238 is the most commonly existing isotope of uranium. It is the most stable isotope with half-life roughly equal to the age of earth. Other two major isotopes of uranium include uranium-235 (which is 0.71% of naturally occurring uranium) and uranium-234 (0.0054% of naturally occurring uranium). Another isotope U-239 is created after the spontaneous fission of U-238. U-233 and uranium-237 are also formed from U-238 [4].
REFERENCES
[1]. “Uranium”. The McGraw-Hill Science and Technology Encyclopedia (5th ed.). The McGraw-Hill Companies, Inc. ISBN 0-07-142957-3.
[2]. Hammond, C. R. (2000). The Elements, in Handbook of Chemistry and Physics (PDF) (81st ed.). CRC press. ISBN 0-8493-0481-4.
[3]. “Nuclear Weapon Design”. Federation of American Scientists. 1998. Archived from the original on 26 December 2008. Retrieved 19 February 2007.
[4]. E. M. Burbidge; G. R. Burbidge; W. A. Fowler; F. Hoyle (1957). “Synthesis of the Elements in Stars” (PDF). Reviews of Modern Physics. 29 (4):547. doi:10.1103/RevModPhys.29.547.