Discoverer: McMillan, Edwin M. and Abelson, Philip H. Discoverer: Glenn T. Seaborg, Joseph W. Kennedy, Edward M. McMillan, Arthur C. Wohl, Discoverer: Glenn T. Seaborg, Ralph A. James, Leon O. Morgan, Albert Ghiorso, Discoverer: Glenn T. Seaborg, Ralph A. James, Albert Ghiorso, Discoverer: Stanley G. Thompson, Glenn T. Seaborg, Kenneth Street, Jr., Albert Ghiorso, Discoverer: Stanley G. Thompson, Glenn T. Seaborg, Bernard G. Harvey, Gregory R. Choppin, Albert Ghiorso, Discoverer: Albert Ghiorso, Glenn T. Seaborg, TorbÃ¸rn Sikkeland, John R. Walton, Discoverer: Albert Ghiorso, TorbjÃ¸rn Sikkeland, Almon E. Larsh, Robert M. Latimer, Copyright 2020 Periodic Table | All Rights Reserved |. The most commonly used spontaneous fission neutron source is the radioactive isotope californium-252. It is a noble metal and a member of the platinum group. Radium is a chemical element with atomic number 88 which means there are 88 protons and 88 electrons in the atomic structure. Its density is about 70% higher than that of lead, and slightly lower than that of gold or tungsten. Barium is the fifth element in group 2 and is a soft, silvery alkaline earth metal. The chemical symbol for Bismuth is Bi. But this âhugeâ space is occupied primarily by electrons, because the nucleus occupies only about 1721Ã10â45 m3 of space. The chemical symbol for Yttrium is Y. Yttrium is a silvery-metallic transition metal chemically similar to the lanthanides and has often been classified as a ârare-earth elementâ. Tantalum is a rare, hard, blue-gray, lustrous transition metal that is highly corrosion-resistant. Lead is a heavy metal that is denser than most common materials. Hafnium is a lustrous, silvery gray, tetravalent transition metal, hafnium chemically resembles zirconium and is found in many zirconium minerals. Why don't libraries smell like bookstores? The chemical symbol for Thorium is Th. The first alloy used on a large scale was bronze, made of tin and copper, from as early as 3000 BC. Although classified as a rare earth element, samarium is the 40th most abundant element in the Earthâs crust and is more common than such metals as tin. We assume no responsibility for consequences which may arise from the use of information from this website. The unit of measure for mass is the atomic mass unit (amu). Argon is the third-most abundant gas in the Earthâs atmosphere, at 0.934% (9340 ppmv). In fact their absorption cross-sections are the highest among all stable isotopes. It is fairly soft and slowly tarnishes in air. Hafniumâs large neutron capture cross-section makes it a good material for neutron absorption in control rods in nuclear power plants, but at the same time requires that it be removed from the neutron-transparent corrosion-resistant zirconium alloys used in nuclear reactors. Typical densities of various substances are at atmospheric pressure. Titanium is a lustrous transition metal with a silver color, low density, and high strength. Selenium is a chemical element with atomic number 34 which means there are 34 protons and 34 electrons in the atomic structure. The chemical symbol for Nobelium is No. The chemical symbol for Krypton is Kr. Discoverer: Scientists at Dubna, Russia (1964)/Albert Ghiorso et. The chemical symbol for Fluorine is F. Fluorine is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. Here are the facts. The chemical symbol for Silver is Ag. The chemical symbol for Copper is Cu. Beryllium is a hard, grayish metal naturally found in mineral rocks, coal, soil, and volcanic dust. al. Erbium is a chemical element with atomic number 68 which means there are 68 protons and 68 electrons in the atomic structure. The chemical symbol for Potassium is K. Potassium was first isolated from potash, the ashes of plants, from which its name derives. All of the alkali metals have a single valence electron in the outer electron shell, which is easily removed to create an ion with a positive charge â a cation, which combines with anions to form salts. It is the eponym of the lanthanide series, a group of 15 similar elements between lanthanum and lutetium in the periodic table, of which lanthanum is the first and the prototype. The mention of names of specific companies or products does not imply any intention to infringe their proprietary rights. Cerium is a chemical element with atomic number 58 which means there are 58 protons and 58 electrons in the atomic structure. Potassium is a chemical element with atomic number 19 which means there are 19 protons and 19 electrons in the atomic structure. Nobelium is a chemical element with atomic number 102 which means there are 102 protons and 102 electrons in the atomic structure. Get your answers by asking now. 0.0899 g/cm3. The chemical symbol for Germanium is Ge. The chemical symbol for Chlorine is Cl. Chromium is a steely-grey, lustrous, hard and brittle metal4 which takes a high polish, resists tarnishing, and has a high melting point. The chemical symbol for Terbium is Tb. Because of its high chemical reactivity, barium is never found in nature as a free element. Manganese is a metal with important industrial metal alloy uses, particularly in stainless steels. Astatine is a chemical element with atomic number 85 which means there are 85 protons and 85 electrons in the atomic structure. It is the fifth most abundant element in Earthâs crust and the third most abundant metal, after iron and aluminium. Neptunium is the first transuranic element. Fermium is a member of the actinide series. Magnesium is a chemical element with atomic number 12 which means there are 12 protons and 12 electrons in the atomic structure. Sodium is a soft, silvery-white, highly reactive metal. Thorium metal is silvery and tarnishes black when exposed to air, forming the dioxide. The chemical symbol for Strontium is Sr. Strontium is an alkaline earth metal, strontium is a soft silver-white yellowish metallic element that is highly reactive chemically. The chemical symbol for Osmium is Os. Lanthanum is a chemical element with atomic number 57 which means there are 57 protons and 57 electrons in the atomic structure. Plutonium is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, and forms a dull coating when oxidized. On the periodic table of the elements, atomic radius tends to increase when moving down columns, but decrease when moving across rows (left to right). The chemical symbol for Californium is Cf. The chemical symbol for Barium is Ba. Approximately 60â70% of thallium production is used in the electronics industry. Hydrogen is a chemical element with atomic number 1 which means there are 1 protons and 1 electrons in the atomic structure. Chemically, sulfur reacts with all elements except for gold, platinum, iridium, tellurium, and the noble gases. This effect is caused by a decrease in the atomic number density. The chemical symbol for Europium is Eu. It is obtained chiefly from the mineral cassiterite, which contains tin dioxide. What is the volume of the earth in cubic centimeters if the radius r of the earth is 6.38 x 108cm? Californium is an actinide element, the sixth transuranium element to be synthesized, and has the second-highest atomic mass of all the elements that have been produced in amounts large enough to see with the unaided eye (after einsteinium). For example, 63Cu (29 protons and 34 neutrons) has a mass number of 63 and an isotopic mass in its nuclear ground state is 62.91367 u. All of its isotopes are radioactive. The chemical symbol for Mercury is Hg. The classical description cannot be used to describe things on the atomic scale. Tellurium is a chemical element with atomic number 52 which means there are 52 protons and 52 electrons in the atomic structure. Francium is an alkali metal, that has one valence electron. Gadolinium is a chemical element with atomic number 64 which means there are 64 protons and 64 electrons in the atomic structure. Praseodymium is a soft, silvery, malleable and ductile metal, valued for its magnetic, electrical, chemical, and optical properties. Commercially, thallium is produced as a byproduct from refining of heavy metal sulfide ores. (1969), Discoverer: Scientists at Dubna, Russia (1967)/Lawrence Berkeley Laboratory (1970), Discoverer: Armbruster, Paula and Muenzenberg, Dr. Gottfried, Element Category: unknown, probably a transition metal, Discoverer: David Anderson, Ruhani Rabin, Team Updraft, Element Category: unknown, probably a post-transition metal, Discoverer: Hisinger, Wilhelm and Berzelius, JÃ¶ns Jacob/Klaproth, Martin Heinrich. Consequently, the smallest atom is helium with a radius of 32 pm, while one of the largest is caesium at 225 pm. It has an estimated density of 40.7 x 103 kg/m3. Gold is thought to have been produced in supernova nucleosynthesis, from the collision of neutron stars. Sulfur is a chemical element with atomic number 16 which means there are 16 protons and 16 electrons in the atomic structure. The metal is found in the Earthâs crust in the pure, free elemental form (ânative silverâ), as an alloy with gold and other metals, and in minerals such as argentite and chlorargyrite. Ruthenium is a chemical element with atomic number 44 which means there are 44 protons and 44 electrons in the atomic structure. The chemical symbol for Antimony is Sb. Samarium is a typical member of the lanthanide series, it is a moderately hard silvery metal that readily oxidizes in air. Rubidium is a soft, silvery-white metallic element of the alkali metal group, with an atomic mass of 85.4678. The chemical symbol for Rhenium is Re. The chemical symbol for Actinium is Ac. When did organ music become associated with baseball? Its boiling point is the lowest among all the elements. The chemical symbol for Rhodium is Rh. Argon is mostly used as an inert shielding gas in welding and other high-temperature industrial processes where ordinarily unreactive substances become reactive; for example, an argon atmosphere is used in graphite electric furnaces to prevent the graphite from burning. Erbium is a silvery-white solid metal when artificially isolated, natural erbium is always found in chemical combination with other elements. Francium is a highly radioactive metal that decays into astatine, radium, and radon. For other isotopes, the isotopic mass usually differs and is usually within 0.1 u of the mass number. Tellurium is a brittle, mildly toxic, rare, silver-white metalloid. The chemical symbol for Sodium is Na. The chemical symbol for Francium is Fr. The chemical properties of this silvery gray, crystalline transition metal are intermediate between rhenium and manganese. Rubidium is a chemical element with atomic number 37 which means there are 37 protons and 37 electrons in the atomic structure. The chemical symbol for Iron is Fe. Mass was no longer considered unchangeable in the closed system. It is occasionally found in native form as elemental crystals. Protactinium is a chemical element with atomic number 91 which means there are 91 protons and 91 electrons in the atomic structure. All isotopes of radium are highly radioactive, with the most stable isotope being radium-226. Compressibility (also known as the coefficient of compressibility is a measure of the relative volume change of a fluid or solid as a response to a pressure (or mean stress) change.