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Bohrium is a synthetic chemical element; it has symbol Bh and atomic number 107. It is named after Danish physicist Niels Bohr. As a synthetic element, it can be created in particle accelerators but is not found in nature. All known isotopes of bohrium are highly radioactive; the most stable known isotope is 270Bh with a half-life of approximately 2.4 minutes, though the unconfirmed 278Bh may have a longer half-life of about 11.5 minutes.
Chemistry is the scientific study of the properties and behavior of matter. It is a physical science within the natural sciences that studies the chemical elements that make up matter and compounds made of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during reactions with other substances. Chemistry also addresses the nature of chemical bonds in chemical compounds.
Lawrencium is a synthetic chemical element; it has symbol Lr and atomic number 103. It is named after Ernest Lawrence, inventor of the cyclotron, a device that was used to discover many artificial radioactive elements. A radioactive metal, lawrencium is the eleventh transuranium element, the third transfermium, and the last member of the actinide series. Like all elements with atomic number over 100, lawrencium can only be produced in particle accelerators by bombarding lighter elements with charged particles. Fourteen isotopes of lawrencium are currently known; the most stable is 266Lr with half-life 11 hours, but the shorter-lived 260Lr is most commonly used in chemistry because it can be produced on a larger scale.
Mendelevium is a synthetic chemical element; it has symbol Md and atomic number 101. A metallic radioactive transuranium element in the actinide series, it is the first element by atomic number that currently cannot be produced in macroscopic quantities by neutron bombardment of lighter elements. It is the third-to-last actinide and the ninth transuranic element and the first transfermium. It can only be produced in particle accelerators by bombarding lighter elements with charged particles. Seventeen isotopes are known; the most stable is 258Md with half-life 51.59 days; however, the shorter-lived 256Md is most commonly used in chemistry because it can be produced on a larger scale.
Nobelium is a synthetic chemical element; it has symbol No and atomic number 102. It is named after Alfred Nobel, the inventor of dynamite and benefactor of science. A radioactive metal, it is the tenth transuranium element, the second transfermium, and is the penultimate member of the actinide series. Like all elements with atomic number over 100, nobelium can only be produced in particle accelerators by bombarding lighter elements with charged particles. A total of twelve nobelium isotopes are known to exist; the most stable is 259No with a half-life of 58 minutes, but the shorter-lived 255No is most commonly used in chemistry because it can be produced on a larger scale.
The periodic table, also known as the periodic table of the elements, is an ordered arrangement of the chemical elements into rows ("periods") and columns ("groups"). It is an icon of chemistry and is widely used in physics and other sciences. It is a depiction of the periodic law, which states that when the elements are arranged in order of their atomic numbers an approximate recurrence of their properties is evident. The table is divided into four roughly rectangular areas called blocks. Elements in the same group tend to show similar chemical characteristics.
Rutherfordium is a synthetic chemical element; it has symbol Rf and atomic number 104. It is named after physicist Ernest Rutherford. As a synthetic element, it is not found in nature and can only be made in a particle accelerator. It is radioactive; the most stable known isotope, 267Rf, has a half-life of about 48 minutes.
In chemistry, a transition metal is a chemical element in the d-block of the periodic table, though the elements of group 12 are sometimes excluded. The lanthanide and actinide elements are called inner transition metals and are sometimes considered to be transition metals as well.
In physics and chemistry, ionization energy (IE) is the minimum energy required to remove the most loosely bound electron of an isolated gaseous atom, positive ion, or molecule. The first ionization energy is quantitatively expressed as
In atomic physics and quantum chemistry, the electron configuration is the distribution of electrons of an atom or molecule in atomic or molecular orbitals. For example, the electron configuration of the neon atom is 1s2 2s2 2p6, meaning that the 1s, 2s, and 2p subshells are occupied by two, two, and six electrons, respectively.
An extended periodic table theorizes about chemical elements beyond those currently known and proven. The element with the highest atomic number known is oganesson (Z = 118), which completes the seventh period (row) in the periodic table. All elements in the eighth period and beyond thus remain purely hypothetical.
A period 7 element is one of the chemical elements in the seventh row of the periodic table of the chemical elements. The periodic table is laid out in rows to illustrate recurring (periodic) trends in the chemical behavior of the elements as their atomic number increases: a new row is begun when chemical behavior begins to repeat, meaning that elements with similar behavior fall into the same vertical columns. The seventh period contains 32 elements, tied for the most with period 6, beginning with francium and ending with oganesson, the heaviest element currently discovered. As a rule, period 7 elements fill their 7s shells first, then their 5f, 6d, and 7p shells in that order, but there are exceptions, such as uranium.
Group 3 is the first group of transition metals in the periodic table. This group is closely related to the rare-earth elements. It contains the four elements scandium (Sc), yttrium (Y), lutetium (Lu), and lawrencium (Lr). The group is also called the scandium group or scandium family after its lightest member.
In chemistry and physics, valence electrons are electrons in the outermost shell of an atom, and that can participate in the formation of a chemical bond if the outermost shell is not closed. In a single covalent bond, a shared pair forms with both atoms in the bond each contributing one valence electron.
In atomic physics and quantum chemistry, the Aufbau principle, also called the Aufbau rule, states that in the ground state of an atom or ion, electrons first fill subshells of the lowest available energy, then fill subshells of higher energy. For example, the 1s subshell is filled before the 2s subshell is occupied. In this way, the electrons of an atom or ion form the most stable electron configuration possible. An example is the configuration 1s2 2s2 2p6 3s2 3p3 for the phosphorus atom, meaning that the 1s subshell has 2 electrons, the 2s subshell has 2 electrons, the 2p subshell has 6 electrons, and so on.
The atomic radius of a chemical element is the distance from the center of the nucleus to the outermost shell of an electron. Since the boundary is not a well-defined physical entity, there are various non-equivalent definitions of atomic radius. Depending on the definition, the term may apply only to isolated atoms, or also to atoms in condensed matter, covalently bound in molecules, or in ionized and excited states; and its value may be obtained through experimental measurements, or computed from theoretical models. Under some definitions, the value of the radius may depend on the atom's state and context.
Superheavy elements, also known as transactinide elements, transactinides, or super-heavy elements, or superheavies for short, are the chemical elements with atomic number greater than 104. The superheavy elements are those beyond the actinides in the periodic table; the last actinide is lawrencium. By definition, superheavy elements are also transuranium elements, i.e., having atomic numbers greater than that of uranium (92). Depending on the definition of group 3 adopted by authors, lawrencium may also be included to complete the 6d series.
Core electrons are the electrons in an atom that are not valence electrons and do not participate directly in chemical bonding. The nucleus and the core electrons of an atom form the atomic core. Core electrons are tightly bound to the nucleus. Therefore, unlike valence electrons, core electrons play a secondary role in chemical bonding and reactions by screening the positive charge of the atomic nucleus from the valence electrons.
In chemistry, periodic trends are specific patterns present in the periodic table that illustrate different aspects of certain elements when grouped by period and/or group. They were discovered by the Russian chemist Dmitri Mendeleev in 1863. Major periodic trends include atomic radius, ionization energy, electron affinity, electronegativity, nucleophilicity, electrophilicity, valency, nuclear charge, and metallic character. Mendeleev built the foundation of the periodic table. Mendeleev organized the elements based on atomic weight, leaving empty spaces where he believed undiscovered elements would take their places. Mendeleev’s discovery of this trend allowed him to predict the existence and properties of three unknown elements, which were later discovered by other chemists and named gallium, scandium, and germanium. English physicist Henry Moseley discovered that organizing the elements by atomic number instead of atomic weight would naturally group elements with similar properties.
References
- ↑ Jørgensen, Christian K. (1988). "Influence of rare earths on chemical understanding and classification". Handbook on the Physics and Chemistry of Rare Earths. Vol. 11. pp. 197–292. doi:10.1016/S0168-1273(88)11007-6. ISBN 9780444870803.
- ↑ Nefedov, V. I.; Trzhaskovskaya, M. B.; Yarzhemskii, V. G. (2006). "Electronic Configurations and the Periodic Table for Superheavy Elements" (PDF). Doklady Physical Chemistry. 408 (Part 2). Pleaides Publishing: 149–151. doi:10.1134/S0012501606060029. S2CID 95738861 . Retrieved 25 September 2020.
configuration interaction is crucial in more than 30% of cases since its consideration leads to another ground-state configuration.
All sources concur with the data above except in the instances listed separately:
NIST
- http://physics.nist.gov/PhysRefData/IonEnergy/ionEnergy.html ; retrieved July 2005, (elements 1–104) based on:
- Atomic Spectroscopy, by W.C. Martin and W.L. Wiese in Atomic, Molecular, & Optical Physics Handbook, ed. by G.W.F. Drake (AIP, Woodbury, NY, 1996) Chapter 10, pp. 135–153.
This website is also cited in the CRC Handbook as source of Section 1, subsection Electron Configuration of Neutral Atoms in the Ground State.
- 91 Pa : [Rn] 5f2(3H4) 6d 7s2
- 92 U : [Rn] 5f3(4Io9/2) 6d 7s2
- 93 Np : [Rn] 5f4(5I4) 6d 7s2
- 103 Lr : [Rn] 5f14 7s2 7p1 question-marked
- 104 Rf : [Rn] 5f14 6d2 7s2 question-marked
CRC
- David R. Lide (ed), CRC Handbook of Chemistry and Physics, 84th Edition, online version. CRC Press. Boca Raton, Florida, 2003; Section 1, Basic Constants, Units, and Conversion Factors; Electron Configuration of Neutral Atoms in the Ground State. (elements 1–104)
- Also subsection Periodic Table of the Elements, (elements 1–103) based on:
- G. J. Leigh, Editor, Nomenclature of Inorganic Chemistry, Blackwell Scientific Publications, Oxford, 1990.
- Chemical and Engineering News, 63(5), 27, 1985.
- Atomic Weights of the Elements, 1999, Pure Appl. Chem., 73, 667, 2001.
WebElements
- http://www.webelements.com/ ; retrieved July 2005, electron configurations based on:
- Atomic, Molecular, & Optical Physics Handbook, Ed. Gordon W. F. Drake, American Institute of Physics, Woodbury, New York, 1996.
- J.E. Huheey, E.A. Keiter, and R.L. Keiter in Inorganic Chemistry : Principles of Structure and Reactivity, 4th edition, Harper Collins, New York, 1993.
- R.L. DeKock and H.B. Gray in Chemical Structure and bonding, Benjamin/Cummings, Menlo Park, California, 1980.
- A.M. James and M.P. Lord in Macmillan's Chemical and Physical Data, Macmillan, London, UK, 1992.
- 103 Lr : [Rn].5f14.7s2.7p1 tentative ; 2.8.18.32.32.9.2 [inconsistent]
- 104 Rf : [Rn].5f14.6d2.7s2 tentative
- 105 Db : [Rn].5f14.6d3.7s2 (a guess based upon that of tantalum) ; 2.8.18.32.32.11.2
- 106 Sg : [Rn].5f14.6d4.7s2 (a guess based upon that of tungsten) ; 2.8.18.32.32.12.2
- 107 Bh : [Rn].5f14.6d5.7s2 (a guess based upon that of rhenium) ; 2.8.18.32.32.13.2
- 108 Hs : [Rn].5f14.6d6.7s2 (a guess based upon that of osmium) ; 2.8.18.32.32.14.2
- 109 Mt : [Rn].5f14.6d7.7s2 (a guess based upon that of iridium) ; 2.8.18.32.32.15.2
- 110 Ds : [Rn].5f14.6d9.7s1 (a guess based upon that of platinum) ; 2.8.18.32.32.17.1
- 111 Rg : [Rn].5f14.6d10.7s1 (a guess based upon that of gold) ; 2.8.18.32.32.18.1
- 112 Cn : [Rn].5f14.6d10.7s2 (a guess based upon that of mercury) ; 2.8.18.32.32.18.2
- 113 Nh : [Rn].5f14.6d10.7s2.7p1 (a guess based upon that of thallium) ; 2.8.18.32.32.18.3
- 114 Fl : [Rn].5f14.6d10.7s2.7p2 (a guess based upon that of lead) ; 2.8.18.32.32.18.4
- 115 Mc : [Rn].5f14.6d10.7s2.7p3 (a guess based upon that of bismuth) ; 2.8.18.32.32.18.5
- 116 Lv : [Rn].5f14.6d10.7s2.7p4 (a guess based upon that of polonium) ; 2.8.18.32.32.18.6
- 117 Ts : [Rn].5f14.6d10.7s2.7p5 (a guess based upon that of astatine) ; 2.8.18.32.32.18.7
- 118 Og : [Rn].5f14.6d10.7s2.7p6 (a guess based upon that of radon) ; 2.8.18.32.32.18.8
Lange
- J.A. Dean (ed), Lange's Handbook of Chemistry (15th Edition), online version, McGraw-Hill, 1999; Section 4, Table 4.1 Electronic Configuration and Properties of the Elements. (Elements 1–103)
- 97 Bk : [Rn] 5f8 6d 7s2
- 103 Lr : [Rn] 4f14 [sic] 6d 7s2
Hill and Petrucci
- Hill and Petrucci, General Chemistry: An Integrated Approach (3rd edition), Prentice Hall. (Elements 1–106)
- 58 Ce : [Xe] 4f2 6s2
- 103 Lr : [Rn] 5f14 6d1 7s2
- 104 Rf : [Rn] 5f14 6d2 7s2 (agrees with guess above)
- 105 Db : [Rn] 5f14 6d3 7s2
- 106 Sg : [Rn] 5f14 6d4 7s2
Hoffman, Lee, and Pershina
Hoffman, Darleane C.; Lee, Diana M.; Pershina, Valeria (2006). "Transactinides and the future elements". In Morss; Edelstein, Norman M.; Fuger, Jean (eds.). The Chemistry of the Actinide and Transactinide Elements (3rd ed.). Dordrecht, The Netherlands: Springer Science+Business Media. p. 1722. ISBN 1-4020-3555-1.
This book contains predicted electron configurations for the elements up to 172, as well as 184, based on relativistic Dirac–Fock calculations by B. Fricke in Fricke, B. (1975). Dunitz, J. D. (ed.). "Superheavy elements a prediction of their chemical and physical properties". Structure and Bonding. 21. Berlin: Springer-Verlag: 89–144. doi:10.1007/BFb0116496. ISBN 978-3-540-07109-9.
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