Electron Configurations. Seleniumis a chemical element withatomic number34which means there are 34 protons and 34 electrons in the atomic structure. Thorium is moderately hard, malleable, and has a high melting point. References (Click the next to a value above to see complete citation information for that entry). It readily forms hard, stable carbides in alloys, and for this reason most of world production of the element (about 80%) is used in steel alloys, including high-strength alloys and superalloys. Complete the electron configurations for all elements in the table provided. E. Discoverer: De Marignac, Charles Galissard, Discoverer: De Marignac, Jean Charles Galissard, Discoverer: Ghring, Otto and Fajans, Kasimir. Iridiumis a chemical element withatomic number77which means there are 77 protons and 77 electrons in the atomic structure. what element is xe 6s2 4f14 5d9 Wearhouse For Sale St Paul, Mn, Jimenez Ja 22 Wood Grips, Labster Immunology Answers, Where To Watch The Outsiders Series, Who Is The Girl In The Girl Biting Lip Meme, Why Isn't Heart And Mind By Kodak On Apple Music, 2p Pusher Arcade Machine, Can Turtles Walk Backwards, Xfinity Dvr Setup, It is the heaviest essential mineral nutrient. Thechemical symbolfor Copper isCu. Thechemical symbolfor Yttrium isY. Yttrium is a silvery-metallic transition metal chemically similar to the lanthanides and has often been classified as a rare-earth element. It is also sometimes considered the first element of the 6th-period transition metals and is traditionally counted among the rare earth elements. 81 terms. Po [Xe]4f14 5d10 6s2 6p5. Mercury is a heavy, silvery d-block element, mercury is the only metallic element that is liquid at standard conditions for temperature and pressure. Thechemical symbolfor Tungsten isW. Tungsten is a rare metal found naturally on Earth almost exclusively in chemical compounds. Os. From the periodic table, Xe has atomic number 54. The cookie is used to store the user consent for the cookies in the category "Analytics". Tabla de Elementos Qumicos # sm. It could be part of the main body, but then the periodic table would be rather long and cumbersome. Very soft and malleable, indium has a melting point higher than sodium and gallium, but lower than lithium and tin. If a subshell is incomplete, then that atom must be in that part of the periodic table. The Aufbau process requires that electrons fill the lowest energy orbitals first. Antimony compounds have been known since ancient times and were powdered for use as medicine and cosmetics, often known by the Arabic name, kohl. Answer: [Kr] 5s1 4d10 silver [Xe] 6s2 4f14 5d7 Iridium [Ar] 4s2 3d10 4p4 selenium [Kr] 5s1 4d4 niobium [Xe] 6s1 4f14 5d10 gold [Kr] 5s2 4d10 5p4 tellurium Explanation: Selenium and tellurium will have the same properties because they both belong to group 16 in the periodic table. 4f14.Electron binding energies. Element Atomic Number Element Symbol Element Electron Configuration; 76: Os [Xe] 4f14 5d6 6s2: 77: Ir [Xe] 4f14 5d7 6s2: 78: Pt [Xe] 4f14 5d9 6s1: 79: Au [Xe] 4f14 5d10 6s1: Osmium - Electron Configuration and Oxidation States - Os, Rhenium - Electron Configuration and Oxidation States - Re, Tungsten - Electron Configuration and Oxidation States - W, Osmium Electron Configuration and Oxidation States Os, Platinum Electron Configuration and Oxidation States Pt. Xenon is a chemical element with symbol Xe and atomic number 54. Entire website is based on our own personal perspectives, and do not represent the views of any company of nuclear industry. Helium is a chemical element with atomic number 2 which means there are 2 protons and 2 electrons in the atomic structure. Terbium is a silvery-white, rare earth metal that is malleable, ductile, and soft enough to be cut with a knife. Ir [Xe]4f14 5d9 6s1. [Xe] 4f14 5d10 6s2 6p2. For example, silicon has nine possible integer oxidation states from 4 to +4, but only -4, 0 and +4 are common oxidation states. Ne 3s23p4 c. Xe 6s24f145d7 d. Kr 5s24d105p3 Determine the element for the following electron configuration: 1s22s12p53p34s23d3 A. Ca B. P C. Ar D. S E. V Write complete electron configuration. Tl [Xe]4f14 5d10 6s2 6p2. What exactly is XE 6s2 4f14 5d6? Thulium is an easily workable metal with a bright silvery-gray luster. Uranium is a silvery-white metal in the actinide series of the periodic table. . Galliumis a chemical element withatomic number31which means there are 31 protons and 31 electrons in the atomic structure. Thechemical symbolfor Ruthenium isRu. It is a member of the chalcogen group on the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds. Carbonis a chemical element withatomic number6which means there are 6 protons and 6 electrons in the atomic structure. In nuclear industry gadolinium is commonly used as a neutron absorber due to very high neutron absorbtion cross-section of two isotopes 155Gd and 157Gd. Originally Answered: [Xe] 6s24f5 is the configuration of which element? Which element has this 1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d10, 4p6, 5s2, 4d10, 5p6, 6s2, 4f14, 5d10, 6p2 configuration? By mass, aluminium makes up about 8% of the Earths crust; it is the third most abundant element after oxygen and silicon and the most abundant metal in the crust, though it is less common in the mantle below. Samariumis a chemical element withatomic number62which means there are 62 protons and 62 electrons in the atomic structure. investFeed What are three interesting facts about iridium? This cookie is set by GDPR Cookie Consent plugin. Thechemical properties of the atomare determined by the number of protons, in fact, by number andarrangement of electrons. [Ne] 3s2 3p1 3. braxton-coleman. [Xe] 6s2 4f14 5d7 2. Rhenium is a silvery-white, heavy, third-row transition metal in group 7 of the periodic table. Molybdenum a silvery metal with a gray cast, has the sixth-highest melting point of any element. You can learn about noble gas configurations at To work backwards and find the element with a given configuration, you first find the noble gas in the Periodic Table. Uranium has the highest atomic weight of the primordially occurring elements. Like all elements with atomic number over 100, nobelium can only be produced in particle accelerators by bombarding lighter elements with charged particles. Niobium (Nb) [Kr] 5s2 4d3. What does it mean that the Bible was divinely inspired? Therefor, it is Iridium. Like the other metals of the platinum group, ruthenium is inert to most other chemicals. Write a ground state electron configuration for each neutral atom. Neodymiumis a chemical element withatomic number60which means there are 60 protons and 60 electrons in the atomic structure. Iodine is the least abundant of the stable halogens, being the sixty-first most abundant element. Use the Aufbau process to fill the orbitals with electrons. Because of this, the first two rows of the periodic table are labeled thes block. Here's the physicist answer. What atom matches this electron configuration Xe 6s2 4f14 5d10? Gold is a transition metal and a group 11 element. The 6s and 6p electrons are in the outermost shell, and are therefore what connection type is known as "always on"? Titanium is resistant to corrosion in sea water, aqua regia, and chlorine. June 17, 2022 . Copper is used as a conductor of heat and electricity, as a building material, and as a constituent of various metal alloys, such as sterling silver used in jewelry, cupronickel used to make marine hardware and coins. Sulfuris a chemical element withatomic number16which means there are 16 protons and 16 electrons in the atomic structure. It is the heaviest element that can be formed by neutron bombardment of lighter elements, and hence the last element that can be prepared in macroscopic quantities. Copyright 2022 DocTHC.com Stout theme by, when did great britain enter world war i brainly, Prince George's County Police Fingerprinting Services, how to stop lips from peeling home remedies, 10 facts about auschwitz concentration camp, 5 types of perceptual illusions psychology, mid plains community college staff directory, genesee hospital rochester ny medical records. Krypton is a member of group 18 (noble gases) elements. answer - Realice la configuracin electrnica para 15 elementos de la tabla peridica cuyos nmeros atmicos se distancien en 3. Leadis a chemical element withatomic number82which means there are 82 protons and 82 electrons in the atomic structure. Feb 18, 2015 at 4:22. By mass, oxygen is the third-most abundant element in the universe, after hydrogen and helium. Thechemical symbolfor Astatine isAt. Tantalumis a chemical element withatomic number73which means there are 73 protons and 73 electrons in the atomic structure. This formula says that lead has all the electrons of xenon as well as the electrons listed after [Xe]. The angels will bring you changes that will improve your love life if you see this, Copyright 2023 TipsFolder.com | Powered by Astra WordPress Theme. Thechemical symbolfor Nickel isNi. Thechemical symbolfor Caesium isCs. Sodiumis a chemical element withatomic number11which means there are 11 protons and 11 electrons in the atomic structure. The element lead has the electron configuration [Xe] 4f14 5d10 6s2 6p2. platinum (Pt), chemical element, the best known and most widely used of the six platinum metals of Groups 810, Periods 5 and 6, of the periodic table. Fritzsche, S., C. Z. Dong, F. Koike, and A. Uvarov. Similarly, thep blockare the right-most six columns of the periodic table, thed blockis the middle 10 columns of the periodic table, while thef blockis the 14-column section that is normally depicted as detached from the main body of the periodic table. [Ne] 3s2 3p1 3. [Xe]6s 2 4f 3. Electron Configuration and Oxidation States of Iridium. Antimony is a lustrous gray metalloid, it is found in nature mainly as the sulfide mineral stibnite. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formula S8. 77 Iridio 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d7. Ernest Z. Barium has the noble gas configuration [Xe]6s. Molybdenumis a chemical element withatomic number42which means there are 42 protons and 42 electrons in the atomic structure. Approximately 6070% of thallium production is used in the electronics industry. Thechemical symbolfor Rhodium isRh. Siliconis a chemical element withatomic number14which means there are 14 protons and 14 electrons in the atomic structure. The Cookies Statement is part of our Privacy Policy. This Electron Configuration table gives the Electron Configuration of all the elements of periodic table . Thechemical symbolfor Thulium isTm. Major advantage of lead shield is in its compactness due to its higher density. 2) How many valence electrons in a species with one Cl, two O, and one unit negative charge a. what element is xe 6s2 4f14 5d7. Flashcards. Significant concentrations of boron occur on the Earth in compounds known as the borate minerals. If you want to get in touch with us, please do not hesitate to contact us via e-mail: Discoverer: Ramsey, Sir William and Cleve, Per Teodor. In example B, which element is represented by the electron configuration? This cookie is set by GDPR Cookie Consent plugin. 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. Now, we have to use the periodic table to find out the name of this element. How could this be?" I see some good answers that are chemistry answers. Your page rank: Total word count: 344. Thechemical symbolfor Molybdenum isMo. Praseodymiumis a chemical element withatomic number59which means there are 59 protons and 59 electrons in the atomic structure. [Xe] 6s2 4f10. al. Thechemical symbolfor Fermium isFm. Chem Notes 01, pages 201-300 Copper. Solve problems easily using our calculators and solvers. What element has an electron configuration of xe 6s2 4f14 5d10 6p2? Under standard conditions, it is the lightest metal and the lightest solid element. Lawrencium is the final member of the actinide series. Correspondingly, which element has the electron configuration Xe 6s2 4f14 5d6? Thechemical symbolfor Holmium isHo. As the most electronegative element, it is extremely reactive: almost all other elements, including some noble gases, form compounds with fluorine. The acid assault is repelled by this element. Lead is soft and malleable, and has a relatively low melting point. antimony atom Thechemical symbolfor Oxygen isO. The electron configuration is the distribution of electrons of an atom or molecule (or other physical structure) in atomic or molecular orbitals. Lead has the highest atomic number of any stable element and concludes three major decay chains of heavier elements. What element is 5p3? Thechemical symbolfor Cobalt isCo. Cobalt is found in the Earths crust only in chemically combined form, save for small deposits found in alloys of natural meteoric iron. Xe is element 54. The expected electron configuration for gold is is [Xe] 6s2 4f14 5d9 but it has been determined to be [Xe] 6s1 4f14 5d10. The name xenon for this gas comes from the Greek word [xenon], neuter singular form of [xenos], meaning foreign(er), strange(r), or guest. Rn. 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, Torbrn Sikkeland, John R. Walton, Discoverer: Albert Ghiorso, Torbjrn Sikkeland, Almon E. Larsh, Robert M. Latimer, Copyright 2023 Periodic Table | All Rights Reserved |. Correct answers: 3 question: [Xe]6s2 4f10 [Xe]6s2 4f14 5d7 [Ne] 3s2 3p1 Whats the element name to each of them? Europium is one of the least abundant elements in the universe. Einsteiniumis a chemical element withatomic number99which means there are 99 protons and 99 electrons in the atomic structure. The chemical symbol for Helium is He. element names in red are gases at room temperature element names in black are solids at room temperature Periodic Table of the Elements [Xe]6s 24f145d5 [Xe]6s24f 145d6 [Xe]6s2 5d7 [Xe]6s14f145d9 [Xe]6s14f145d10 [Xe]6s24f145d10 4f145d106p1 3 2 14 (i) [Kr] 5s1 4d10 (ii) [Xe] 6s2 4f14 5d7 (iii) [Ar] 4s2 3d10 4p4 (iv) [Kr] 5s1 4d4 (v) [Xe] 6s1 4f14 5d10 (vi) [Kr] 5s2 4d10 5p4 (b) Based on the electron configurations in part (a), which of the identified Browse. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Ernest Z. Barium has the noble gas configuration [Xe]6s. Example 3: The electronic configuration of a neutral LeadAtom is Xe) 6s? Rheniumis a chemical element withatomic number75which means there are 75 protons and 75 electrons in the atomic structure. Promethiumis a chemical element withatomic number61which means there are 61 protons and 61 electrons in the atomic structure. Thechemical symbolfor Lanthanum isLa. Promethium (Pm) is a Lanthanide element with the atomic number 61. Thechemical symbolfor Indium isIn. Nobelium is the tenth transuranic element and is the penultimate member of the actinide series. Calculate the number of electrons or protons in the given configuration in a simple way to get this answer. Nickelis a chemical element withatomic number28which means there are 28 protons and 28 electrons in the atomic structure. Xe 131.3 5s2,5p6 55 Cs 133 6s1 56 Ba 137.3 6s2 57 La 139 5d1,6s2 58 Ce 140 4f1,5d1,6s2 59 Pr 141 4f3,6s2 60 Nd 144 4f4,6s2 61 Pm 145 4f5,6s2 62 Sm 150.5 H He Li Be B C N O F Ne Na Mg Al . Promethium is one of only two such elements that are followed in the periodic table by elements with stable forms. Pb [Xe]4f14 5d10 6s2 6p3. Osmium [Xe] 4f14 5d6 6s2. Neon is a colorless, odorless, inert monatomic gas under standard conditions, with about two-thirds the density of air. A very heavy, precious, silver-white metal, platinum is soft and ductile and has a high melting point and good resistance to corrosion and chemical attack. (Enter the chemical symbol or name of the element.) Actinium is a soft, silvery-white radioactive metal. Thechemical symbolfor Mendelevium isMd. Zirconium is mainly used as a refractory and opacifier, although small amounts are used as an alloying agent for its strong resistance to corrosion. Tungsten is an intrinsically brittle and hard material, making it difficult to work. Thechemical symbolfor Bromine isBr. kmassarotti is looking for your assistance. Thechemical symbolfor Germanium isGe. Writing Electron . Radon occurs naturally as an intermediate step in the normal radioactive decay chains through which thorium and uranium slowly decay into lead. You'll get a detailed solution from a subject matter expert that helps you learn core concepts. Thechemical symbolfor Scandium isSc. The element lead has the electron configuration [Xe] 4f14 5d10 6s2 6p2. Titanium is a lustrous transition metal with a silver color, low density, and high strength. Click on 'Element Atomic Number', 'Element Symbol', 'Element Name' and 'Element Electron Configuration ' headers to sort. Thechemical symbolfor Dysprosium isDy. Thechemical symbolfor Thorium isTh. You Are Here: will my player transfer to 2k22 next gen texas roadhouse call ahead seating rules what element is xe 6s2 4f14 5d7. Thechemical symbolfor Boron isB. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal. What element is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s1? How do you make tulips last longer in a vase? The two common oxidation numbers of lead are lead(II) when the two 6p2 electrons are lost and lead(IV) when the two 6s2 electrons are also oxidized. What element has the electron configuration Kr 5s2 4d10 5p3? Barium is the fifth element in group 2 and is a soft, silvery alkaline earth metal. The ninth member of the lanthanide series, terbium is a fairly electropositive metal that reacts with water, evolving hydrogen gas. Lutetium is the last element in the lanthanide series, and it is traditionally counted among the rare earths. Neonis a chemical element withatomic number10which means there are 10 protons and 10 electrons in the atomic structure. Thorium is a naturally-occurring element and it is estimated to be about three times more abundant than uranium. Start studying Periodic Table of Elements. Tin is a post-transition metal in group 14 of the periodic table. Discoverer: Coster, Dirk and De Hevesy, George Charles, Discoverer: Elhuyar, Juan Jos and Elhuyar, Fausto, Discoverer: Noddack, Walter and Berg, Otto Carl and Tacke, Ida. Thechemical symbolfor Beryllium isBe. By convention, they are written last in noble gas configuration. Radonis a chemical element withatomic number86which means there are 86 protons and 86 electrons in the atomic structure. Titanium condenser tubes are usually the best technical choice, however titanium is very expensive material. Osmium. Gallium (Ga) [Ar] 4s2 3d10 4p1 [Ne] 3s1. By clicking Accept All, you consent to the use of ALL the cookies. Thechemical symbolfor Sodium isNa. Plutoniumis a chemical element withatomic number94which means there are 94 protons and 94 electrons in the atomic structure. It has 2 valence electrons. [Kr] 5s2 4d10 5p3. Silicon is a hard and brittle crystalline solid with a blue-grey metallic lustre, it is a tetravalent metalloid and semiconductor. It must be element 56. It is even less abundant than the so-called rare earths. Because of its high chemical reactivity, barium is never found in nature as a free element. Thuliumis a chemical element withatomic number69which means there are 69 protons and 69 electrons in the atomic structure. The number of electrons in each elements electron shells, particularly the outermost valence shell, is the primary factor in determining its chemical bonding behavior. The element is helium. Which element has the electron configuration Xe 6s2 4f14 5d10 6p2? Dysprosium is used for its high thermal neutron absorption cross-section in making control rods in nuclear reactors, for its high magnetic susceptibility in data storage applications. Argon is the third-most abundant gas in the Earths atmosphere, at 0.934% (9340 ppmv). Thechemical symbolfor Fluorine isF. Fluorine is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. What element is Xe 6s2 4f14 5d8? 5 reactivos biolgicos -Descripcin -Riesgos -Uso . 1. Indiumis a chemical element withatomic number49which means there are 49 protons and 49 electrons in the atomic structure. June 7, 2022 . Einsteinium is the seventh transuranic element, and an actinide. How To write an electron configuration. Most elements have more than one possible oxidation state. In the periodic table, the elements are listed in order of increasing atomic number Z. Like all elements with atomic number over 100, lawrencium can only be produced in particle accelerators by bombarding lighter elements with charged particles. A magnesium atom has 12 electrons, which means it has 12 electrons. The 6s and 6p electrons are in the outermost shell, and are therefore the valence electrons. Purchases, The Gotham Group (The Maze Runner) and EveryWhere Studios are working on a film based on Sharon Drapers inspiring young adult novel Out of My, Gina is an Italian-born Queen who means Queen. Gina is a name that has been used by parents considering girls baby names. [Ar] 3d10 4s2 4p2. 0,00 . To work backwards and find the element with a given configuration, you first find the noble gas in the Periodic Table. Zinc (Zn) [Ar] 4s2 3d10. 16 b. The first alloy used on a large scale was bronze, made of tin and copper, from as early as 3000 BC. Memrise Blog Engineering Blog Press. Cerium is the element that has the electron configuration of Xe 6s2 5d1 4f1. Mt first question is why Pt's configuration is. But opting out of some of these cookies may affect your browsing experience. Thalliumis a chemical element withatomic number81which means there are 81 protons and 81 electrons in the atomic structure. These cookies ensure basic functionalities and security features of the website, anonymously. how to get to quezon avenue mrt station Uncovering hot babes since 1919. So, an antimony atom with charge +2 has an electron configuration of 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p1. The bulk properties of astatine are not known with any certainty. (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, Jns Jacob/Klaproth, Martin Heinrich. Nickel belongs to the transition metals and is hard and ductile. There are over 100 different borate minerals, but the most common are: borax, kernite, ulexite etc. what element is xe 6s2 4f14 5d7. Yttriumis a chemical element withatomic number39which means there are 39 protons and 39 electrons in the atomic structure. Cerium is a soft, ductile and silvery-white metal that tarnishes when exposed to air, and it is soft enough to be cut with a knife. This formula says that lead has all the electrons of xenon as well as the electrons listed after [Xe]. ; 4 Which element has the electron configuration Kr 5s2 4d10 5p3? This problem has been solved! The element of this atomic number is lead, Pb. 2) You may not distribute or commercially exploit the content, especially on another website. Possible oxidation states are +3,4. You wrote: [Xe] 6s2, 4f14, 5d9. Xe is element 54. braxton-coleman. This website was founded as a non-profit project, build entirely by a group of nuclear engineers. Which element has an electronic configuration of Xe 4f14 5d10 6s2? Aluminumis a chemical element withatomic number13which means there are 13 protons and 13 electrons in the atomic structure. Electron Configuration Chart - Electron Configuration of all the elements in table chart. . Thechemical symbolfor Francium isFr. It occurs on Earth as the decay product of various heavier elements. Thechemical symbolfor Manganese isMn. Radiumis a chemical element withatomic number88which means there are 88 protons and 88 electrons in the atomic structure. SchoolMyKids.com is part of the ParentsNKids Network. Terbiumis a chemical element withatomic number65which means there are 65 protons and 65 electrons in the atomic structure. Thechemical symbolfor Hydrogen isH. With a standard atomic weight of circa 1.008, hydrogen is the lightest element on the periodic table. What element is xe 6s2 4f14 5d6. Thechemical symbolfor Antimony isSb. Indium is a post-transition metal that makes up 0.21 parts per million of the Earths crust. Nearly all technetium is produced synthetically, and only minute amounts are found in the Earths crust. The element lead has the electron configuration [Xe] 4f14 5d10 6s2 6p2. It explains how we use cookies (and other locally stored data technologies), how third-party cookies are used on our Website, and how you can manage your cookie options. Boronis a chemical element withatomic number5which means there are 5 protons and 5 electrons in the atomic structure. 2. Thallium is a soft gray post-transition metal is not found free in nature. Look up the Periodic Table, and for #Z=82#, you find #"Pb"#. Emsley, John. What is the ground state electron configuration of the element germanium? Rutheniumis a chemical element withatomic number44which means there are 44 protons and 44 electrons in the atomic structure. [Xe] 4f14 5d2 6s2 Transition metals. Illustrate with a box diagram. Osmium. Naturally occurring potassium is composed of three isotopes, of which 40K is radioactive. [Rn]7s 2 5f 14 6d 10 7p 5 [note] Praseodymium.