which is the rarest element ?
545668
"The element was actually discovered by Perrier and Segre in Italy in\n1937. It was found in a sample of molybdenum, which was bombarded by\ndeuterons in the Berkeley cyclotron, and which E. Lawrence sent to\nthese investigators. Technetium was the first element to be produced\nartificially. Since its discovery, searches for the element in\nterrestrial material have been made without success. If it does exist,\nthe concentration must be very small."\n\nTellurium, a metalloid, which can be found in group 7A was first discovered by German scientist Franz Joseph Muller von Reichenstien, but was recognized 16 years later in 1798 as a element and given its name by the German chemist Martin Heinrich Klaproth. Tellurium ranks about 78th in natural abundance. It occurs in the pure state or is found in combination with gold, silver, copper, lead, and nickel in such minerals as sylvanite, petzite, and tetradymite. Tellurium meltsa about 452 degrees C, boils about 1390 degrees C, and has a specific gravity of 6.25. Tellurium is one of the rareest elements. Its compunds are toxic, and the element itself plays no known role in living organisms. Tellurium is used in manufacturing rectifiers and thermoelectric devices. It is employed as a vulcanizing agent in the processing of natural and synthetic rubber.
232753
An atom is the smallest divisible partical that can exist on its own. Its divisibble because it contains three subatomical particals known as protons, neurons, and electrons while an element is a substance that cannot be split into two or more substance like the periodic table has a list of different elements, so examples of elements are those on the periodic table and atoms make up matter.
887068
Element 118 may have been found about two weeks ago:\n\nhttp://www.fogcityjournal.com/news_in_brief/bcn_livermore_labs_element_118_061016.shtml
441392
What element has the highest density?\n\n    Studies show that osmium and iridium share the highest densities. The reason why there are two is because there are slight discrepancies between the different measurement systems. Speaking of densities, a pinhead's volume of a piece of a dwarf star would weight more than the earth.
752142
The element with the largest atomic radius is cesium.  Its electronic configuration is [Xe] 6s1.\n\nFrancium could be larger but I do not believe there is data on its atomic radius yet.
239566
no, the densest metal is NOT uranium, it is the heaviest natural element, but it is the the most compacted, and therefore, dense, the densest element is Iridium at 22.5 g/cm3. uranium's density is only 18.95 g/cm3 at 20 C.
843681
Si is the most abundant mineral element, but feldspar would be the most abundant mineral as far as rocks & minerals. Quartz comes in second.
657306
Some elements are not natural to earth, and were brought here by meteroites and such things that crashed into Earth (and still crash into today). Some of the heavy metals, especially...certain other elements. \n\nSome are just unstable elements or compounds, and so they break down rather quickly, especially the radioactive ones where their half-lives are as short as days or minutes. Or are man-made.\n\nYou also have to go down to the basics of Chemistry. Some elements HATE to be alone, they are unstable in their groundstates, and they like to bond with other atoms to form compounds.\n\n"Elements 58 to 71 (on the periodic table) are known as lanthanide or rare earth elements. These elements are found on earth in only very small amounts.\nElements 90 to 103 are known as the actinide elements. They include most of the will known elements which are found in nuclear reactions. The elements with larger atomic numbers than 92 do not occur naturally. They have all been produced artificially by bombarding other elements with particles.\n\n\nThere are a wide array of reason as to why some elements are more rare. I hope this shed a little bit of light to your question.
803576
Element UUo, atomic number 118, is officially un-named and un-discovered according to the folks at Los Alamos. See their web site.\n\n(http://periodic.lanl.gov/elements/118.html\n\nHowever, I think this element should be named Unobtanium since no one can seem to find it.
974643
Common elements that exist as diatomic molecules are H, N, O, F, Cl, Br, and I.\n\nSo these elements are most commonly found in nature as H2, N2, O2, F2, Cl2, Br2, and I2.
754664
Los Alamos national lab has a good periodic table/ elemental factoids.\n\nLanthanum is La.  It is the beginning of the "Lanthanides".
834216
Radium. Anyway, pitchblende is a uranium ore, and according to wikipedia--\n7 metric tons of pitchblende yields 1 gram of radium\n\nOr maybe pure Francium, another element. It is so rare and reactive that it has never been extracted and investigated properly. All scientists know is of it's existence.\n\nSee: it has been estimated that there might be only from 340 to 550 grams [1] of francium in the earth's crust at any one time.\n\nBut it's probably got to be Astatine--it is the rarest element on earth, even more so than francium.\n\nOh well.
789061
the least expensive are probably the ones that are most commonly found and easily acquired. oxygen, helium, aluminum, chlorine, sodium...\n\nthe most expensive...well radium and other radioactive materials that are used in nuclear reaction. precious metals like platinum and gold.
515033
The most abundant element in the universe is hydrogen.  Nebulae are made up most of that and "dust".
1013566
For common metals, iron is pretty much all you have.  Magnetite is an oxide of iron that is the about the most magnetic metal on earth.\n If you are looking for low weight, rare earth magnets are the way to go, but will cost you accordingly.  Neodymium or Samarium-Cobalt are your best bets there.
139410
ignoring radioactivity(which deals with unstable isotopes) the elements are indestructible and will last forever.\nthe law of conservation of matter says matter can never be created nor destroyed.( we can destroy matter in nuclear bombs but otherwise...).\nAs long as atoms exist, which is forever, the periodic table will tell you what to expect.
612990
At the bottom of the perodic table...\n\nThey are technetium (at. no. 43), which was the first element to be synthesized, promethium (at. no. 61), astatine (at. no. 85), francium (at. no. 87), and the transuranium elements (at. no. 93 and beyond in the periodic table). Some of these elements have since been shown to exist in minute amounts in nature, usually as short-lived members of natural radioactive decay series (see radioactivity).\n\nThe synthetic elements through at. no. 100 (fermium) are created by bombarding a heavy element, such as uranium or plutonium, with neutrons or alpha particles. The synthesis of the transfermium elements (elements with at. no. 101 or greater) is accomplished by the fusion of the nuclei of two lighter elements. Elements 101 through 106 were first produced by fusing the nuclei of slightly lighter elements, such as californium, with those of light elements, such as carbon. Elements 107 through 112 were first produced by fusing the nuclei of medium-weight elements, such as bismuth or lead, with those of other medium-weight elements, such as iron, nickel, or zinc. Element 114 was first produced by fusing the nuclei of plutonium and calcium and subsequently by fusing the nuclei of lead and krypton, as was element 116. Element 115 was produced by bombarding americium with calcium, and element 113 resulted from the radioactive decay of element 115. The claim by Lawrence Berkeley National Laboratory to have created element 118 has been retracted.)\n\nThe transfermium elements are produced in very small quantities (one atom at a time), and identification is therefore very difficult because of half-lives ranging from minutes to milliseconds and the need to identify the products by methods other than known chemical separations. This has led to controversy over reported discoveries and over the naming of the elements. It has been predicted that one isotope of element 114—containing 114 protons and 184 neutrons—would be very stable because its nucleus would have a full complement of protons and neutrons. Termed an “island of stability,” its half-life might be measured in years. However, none of the three isotopes of element 114 synthesized as yet have as many as 184 neutrons, and their half-lives are still in the millisecond range.