Abundance and Measurement of Stable Isotopes

1999 ◽  
Author(s):  
Robert E. Criss
Keyword(s):  
Nineteenth Century ◽  
Stable Isotopes ◽  
Periodic Table ◽  
Chemical Properties ◽  
Atomic Theory ◽  
Casual Reader ◽  
Chemical Knowledge ◽  
Uranium Minerals ◽  
Key Aspects ◽  
Great Advance

The discovery of isotopes is best understood in the context of the spectacular advances in physics and chemistry that transpired during the last 200 years. Around the year 1800, compounds and elements had been distinguished. About 39 elements were recognized, and discoveries of new elements were occurring rapidly. At about this time, the chemist John Dalton revived the ancient idea of the atom, a word derived from the Greek “atomos,” which literally means “indivisible.” According to Dalton’s theory, all matter is made of atoms which are immutable and which cannot be further subdivided. Moreover, Dalton argued that all atoms of a given element are identical in all respects, including mass, but that atoms of different elements have different masses. Even today, Dalton’s atomic theory would be accepted by a casual reader, yet later developments have shown that it is erroneous in almost every one of its key aspects. Nevertheless, Dalton’s concept of the atom was a great advance, and, with it, he not only produced the first table of atomic weights, but also generated the concept that compounds comprise elements combined in definite proportions. His theory laid the groundwork for many other important advances in early nineteenth-century chemistry, including Avogadro’s 1811 hypothesis that equal volumes of gas contain equal numbers of particles, and Prout’s 1815 hypothesis that the atomic weights of the elements are integral multiples of the weight of hydrogen. By 1870, approximately 65 elements had been identified. In that year, Mendeleev codified much of the available chemical knowledge in his “periodic table,” which basically portrayed the relationships between the chemical properties of the elements and their atomic weights. The regularities that Mendeleev found directly lead to the discovery of several “new” elements—for example, Sc, Ga, Ge, and Hf—that filled vacancies in his table and confirmed his predictions of their chemical properties and atomic weights. Similarly, shortly after Rayleigh and Ramsay isolated Ar from air in 1894, the element He was isolated from uranium minerals in 1895; the elements Ne, Kr, and Xe were found in air in 1898; and Rn was discovered in 1900.

Twinkle, Twinkle Little Star

2019 ◽  
pp. 46-53
Author(s):  
Nicholas Mee
Keyword(s):  
Nineteenth Century ◽  
Quantum Mechanics ◽  
Chemical Composition ◽  
Hydrogen Atom ◽  
Periodic Table ◽  
Chemical Properties ◽  
Spectral Lines ◽  
Exclusion Principle ◽  
Middle Years ◽  
Absorption Of Light

The emission and absorption of light by atoms produces discrete sets of spectral lines that were a vital clue to unravelling the structure of atoms and their elucidation was an important step towards the development of quantum mechanics. In the middle years of the nineteenth century Bunsen and Kirchhoff discovered that spectral lines can be used to determine the chemical composition of stars. Following Rutherford’s discovery of the nucleus, Bohr devised a model of the hydrogen atom that explained the spectral lines that it produces. His work was developed further by Pauli, who postulated the exclusion principle in order to explain the structure of other types of atom. This enabled him to explain the layout of the Periodic Table and the chemical properties of the elements.

The Periodic Table: A Very Short Introduction

2019 ◽  
Author(s):  
Eric R. Scerri
Keyword(s):  
Quantum Mechanics ◽  
Atomic Number ◽  
Periodic Table ◽  
Chemical Elements ◽  
Chemical Properties ◽  
Electron Configuration ◽  
Short Introduction ◽  
Atomic Theory ◽  
Recent Advances

The periodic table of elements provides an arrangement of the chemical elements, ordered by their atomic number, electron configuration, and recurring chemical properties. The Periodic Table: A Very Short Introduction considers what led to the table’s construction and shows how the deeper meaning of its structure gradually became apparent with the development of atomic theory and quantum mechanics, which underlies the behaviour of all of the elements and their compounds. This new edition celebrates the completion of the seventh period of the table, with the ratification and naming of elements 113, 115, 117, and 118 as nihonium, moscovium, tennessine, and oganesson, and incorporates recent advances in our understanding of the origin of the elements.

A Well-Ordered Thing

2018 ◽  
Author(s):  
Michael D. Gordin
Keyword(s):  
Nineteenth Century ◽  
History Of Science ◽  
Periodic Table ◽  
The Arctic ◽  
Classic Work ◽  
Hot Air ◽  
History Of ◽  
First Time

Dmitrii Mendeleev (1834–1907) is a name we recognize, but perhaps only as the creator of the periodic table of elements. Generally, little else has been known about him. This book is an authoritative biography of Mendeleev that draws a multifaceted portrait of his life for the first time. As the book reveals, Mendeleev was not only a luminary in the history of science, he was also an astonishingly wide-ranging political and cultural figure. From his attack on Spiritualism to his failed voyage to the Arctic and his near-mythical hot-air balloon trip, this is the story of an extraordinary maverick. The ideals that shaped his work outside science also led Mendeleev to order the elements and, eventually, to engineer one of the most fascinating scientific developments of the nineteenth century. This book is a classic work that tells the story of one of the world's most important minds.

scholarly journals Discipleship in Oriental Orthodox and Evangelical Communities

Religions ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 320
Author(s):  
Ralph Lee
Keyword(s):  
Nineteenth Century ◽  
Spiritual Disciplines ◽  
Way Of Life ◽  
Literary Works ◽  
Orthodox Christian ◽  
The Bible ◽  
Revival Movements ◽  
Key Aspects ◽  
Evangelical Protestant

In many countries with a strong Orthodox Christian presence there are tensions between Evangelicals and Orthodox Christians. These tensions are rooted in many theological, ecclesiological, and epistemological differences. In practice, one of the crucial causes of tension comes down to different practical understandings of what a Christian disciple looks like. This paper examines key aspects of discipleship as expressed in revival movements in Orthodox Churches Egypt, India and Ethiopia which are connected to the challenges presented by the huge expansion of Evangelical Protestant mission from the nineteenth century. Key aspects will be evaluated in comparison with aspects that are understood to characterize disciples in Evangelical expressions, including: differing understandings of the sacraments and their place in the life of a disciple; ways in which different traditions engage with the Bible and related literary works; contrasting outlooks on discipleship as an individual and a community way of life; and differing understanding of spiritual disciplines.

scholarly journals Role of the periodic table in discovery of new elements

2011 ◽  
Vol 1 (1) ◽  
pp. 1-5 ◽  
Author(s):  
D.C. Hoffman
Keyword(s):  
Periodic Table ◽  
Predictive Power ◽  
Chemical Elements ◽  
Chemical Properties ◽  
Negative Effects ◽  
Current Form ◽  
Future Role ◽  
History Of ◽  
Chemical Techniques

AbstractThis year (2009) marks the 140th Anniversary of Mendeleev's original 1869 periodic table of the elements based on atomic weights. It also marks the 175th anniversary of his birth in Tolbosk, Siberia. The history of the development of periodic tables of the chemical elements is briefly reviewed beginning with the presentation by Dmitri Mendeleev and his associate Nikolai Menshutkin of their original 1869 table based on atomic weights. The value, as well as the sometimes negative effects, of periodic tables in guiding the discovery of new elements based on their predicted chemical properties is assessed. It is noteworthy that the element with Z=101 (mendelevium) was identified in 1955 using chemical techniques. The discoverers proposed the name mendelevium to honor the predictive power of the Mendeleev Periodic Table. Mendelevium still remains the heaviest element to have been identified first by chemical rather than nuclear or physical techniques. The question concerning whether there will be a future role for the current form of the periodic table in predicting chemical properties and aid in the identification of elements beyond those currently known is considered.

The Changing Relation between Atomicity and Elementarity

2020 ◽  
pp. 87-108
Author(s):  
Marina P. Banchetti-Robino
Keyword(s):  
Nineteenth Century ◽  
Quantitative Analysis ◽  
Chemical Analysis ◽  
Early Modern ◽  
Current Understanding ◽  
Atomic Theory ◽  
Chemical Revolution ◽  
Fundamental Nature ◽  
Form Compound ◽  
Nature Of Matter

Early modern efforts to reconceptualize atomicity as a chymical notion fell by the wayside during the chemical revolution, as Antoine Lavoisier’s desire to transform chemistry into a strictly empirical and quantitative science led him to reject all metaphysical speculation about the fundamental nature of matter. Instead, Lavoisier focused on identifying elementary substances, which he defined operationally as the final products of chemical analysis. Our current understanding of the relation between atoms and elements, however, owes a great deal to the work of nineteenth-century chemist John Dalton. Dalton’s chemical atomic theory reconciled the concepts of “atomicity” and “elementarity” and rendered both as empirical and chemical notions, amenable to measurement and quantitative analysis. One of the central goals of Dalton’s theory was understanding how relative weights of chemical atoms determine the properties of elements and how the chemical atoms of different elements combine to form compound substances. Thus, Dalton’s theory provided a way of studying and measuring the properties of atoms and elements in a way that allowed chemists to finally understand the chemical relations between them.

Diamonds are Forever and Zirconium is for Submarines

2013 ◽  
Author(s):  
Lars Öhrström
Keyword(s):  
Transition Metals ◽  
Periodic Table ◽  
Chemical Properties ◽  
Pure Metal ◽  
Cubic Zirconia ◽  
Love Story ◽  
Zirconium Silicate ◽  
Similar Chemical ◽  
Engagement Rings

The appearance of a diamond engagement ring in the long and convoluted love story between Botswana’s First Lady Detective, Mma Ramotswe, and the owner and brilliant mechanic of Tlokweng Road Speedy Motors, Mr J. L. B. Matekoni, seems to signal an end to this particular sub-plot, stretching over several volumes of Alexander McCall Smith’s bestselling and original series of crime novels (that we met in Chapter 1). However, a slight problem involving cubic zirconia is discovered, and the story lingers on until the next book in the series. Similar names for elements and their compounds are a nuisance in chemistry, but oft en arise historically, and zirconium is just one such example. Apart from the pure metal we have zircon and zirconia, all three of which have important applications. Zircon is zirconium silicate, with the formula ZrSiO4, and cubic zirconia is a special form of zirconium dioxide, ZrO2. The latter, as you may have guessed, is an excellent diamond substitute in, among other applications, engagement rings. We are not going to dwell on the details of the element zirconium, but you should know that within the Periodic Table it is located in the large middle chunk called the transition metals. You have probably heard of its cousin titanium, immediately above it, and a sibling, hafnium, straight down the ladder. Why do I call them siblings? Because in the Periodic Table elements in the same column tend to have similar chemical properties. In particular, in the family of transition metals in the central section containing 27 elements—each with a number of properties in common—the two lower elements in each column tend to be the most similar. The similar chemical properties of zirconium and titanium means that we can usually find zirconium where we mine the much more plentiful titanium, and also that once we have separated the titanium from zirconium there will be a small quantity of hafnium trailing along—an impurity that is much harder to get rid of. The sleek jeweller in Gaborone will not care if his fake diamonds contain trace levels of HfO2 mixed with the ZrO2.

Introduction: Why oxygen chemstry?

1992 ◽  
Author(s):  
Donald T. Sawyer ◽  
R. J. P. Williams
Keyword(s):  
Organic Chemistry ◽  
Nineteenth Century ◽  
Chemical Properties ◽  
First Year ◽  
Chemistry Curriculum ◽  
Design And Synthesis ◽  
Carbon Molecules ◽  
Living Organisms ◽  
Fixed Array ◽  
Oxygen Atoms

The fundamental premise of chemistry is that all matter consists of molecules. The physical and chemical properties of matter are those of the constituent molecules, and the transformation of matter into different materials (compounds) is the result of their reactions to form new molecules. A molecule consists of two or more atoms held in a relatively fixed array via valence-electron orbital overlap (covalent bonds; chemical bonds). In the nineteenth century chemists focused on the remarkable diversity of molecules produced by living organisms, which have in common the presence of tetravalent carbon atoms. As a result the unique versatility of carbon for the design and synthesis of new molecules was discovered, and the subdiscipline of organic chemistry (the science of carbon-containing molecules) has become the dominant part of the discipline. Clearly, the results from a focus on carbon-based chemistry have been immensely useful to science and to society. Although most molecules in biological systems [and produced by living organisms (particularly aerobic systems)] contain oxygen atoms as well as carbon and hydrogen (e.g., proteins, nucleic acids, carbohydrates, lipids, hormones, and vitamins), there has been a long tradition in all of chemistry to treat oxygen atoms as “neutral counterweights” for the “important,” character-determining elements (C, H, Al, Si, Fe, I) of the molecule. Thus, chemists have tended to take the most important element (oxygen) for granted. The chemistry curriculum devotes one or two year-courses to the chemistry of carbon (“Organic Chemistry”), but only a brief chapter on oxygen is included in the first-year and the inorganic courses. However, if the multitude of hydrocarbon molecules is from the incorporation of oxygen atoms in single-carbon molecules argues against the assignment of a “neutral character” for oxygen atoms [e.g., Cn(graphite), CH4(g), CH3OH(1), CH2(O)(1), HC(O)OH(1), (HO)2C(O)(aq), CO(g), CO2(g)]. Just as the focus of nineteenth century chemists on carbon-containing molecules has produced revolutionary advances in chemical understanding, and yielded the technology to synthesize and produce useful chemicals, polymers, and medicinals; I believe that a similar focus on oxygen chemistry is appropriate and will have analogous rewards for chemistry, biochemistry, and the chemical process technologies.

Quantum Mechanics and the Periodic Table

2019 ◽  
Author(s):  
Eric Scerri
Keyword(s):  
Quantum Mechanics ◽  
Quantum Theory ◽  
Periodic Table ◽  
Chemical Properties ◽  
Pauli Exclusion Principle ◽  
Niels Bohr ◽  
Exclusion Principle ◽  
Old Quantum Theory ◽  
Set Up ◽  
Three Body

In chapter 7, the influence of the old quantum theory on the periodic system was considered. Although the development of this theory provided a way of reexpressing the periodic table in terms of the number of outer-shell electrons, it did not yield anything essentially new to the understanding of chemistry. Indeed, in several cases, chemists such as Irving Langmuir, J.D. Main Smith, and Charles Bury were able to go further than physicists in assigning electronic configurations, as described in chapter 8, because they were more familiar with the chemical properties of individual elements. Moreover, despite the rhetoric in favor of quantum mechanics that was propagated by Niels Bohr and others, the discovery that hafnium was a transition metal and not a rare earth was not made deductively from the quantum theory. It was essentially a chemical fact that was accommodated in terms of the quantum mechanical understanding of the periodic table. The old quantum theory was quantitatively impotent in the context of the periodic table since it was not possible to even set up the necessary equations to begin to obtain solutions for the atoms with more than one electron. An explanation could be given for the periodic table in terms of numbers of electrons in the outer shells of atoms, but generally only after the fact. But when it came to trying to predict quantitative aspects of atoms, such as the ground-state energy of the helium atom, the old quantum theory was quite hopeless. As one physicist stated, “We should not be surprised . . . even the astronomers have not yet satisfactorily solved the three-body problem in spite of efforts over the centuries.” A succession of the best minds in physics, including Hendrik Kramers, Werner Heisenberg, and Arnold Sommerfeld, made strenuous attempts to calculate the spectrum of helium but to no avail. It was only following the introduction of the Pauli exclusion principle and the development of the new quantum mechanics that Heisenberg succeeded where everyone else had failed.

4. The eightfold path: organizing the elements

2004 ◽  
pp. 65-90
Author(s):  
Philip Ball
Keyword(s):  
Quantum Theory ◽  
Periodic Table ◽  
Atomic Theory ◽  
Subatomic Particles ◽  
Jean Perrin

‘The eightfold path: organizing the elements’ explains the history and rationale of the Periodic Table. Atomic theory was not fully accepted until Jean Perrin proved the existence of atoms in 1908. Rutherford et al went further, elucidating subatomic particles. This provided new insights into the Periodic Table, created decades earlier by Mendeleyev. Mendeleyev was not the first to attempt to group the elements. However, an improved set of atomic weights published in 1860 caused an upsurge in research. Mendeleyev's Table showed the order underlying the elements, left gaps for new elements, and questioned irreconcilable data. This data was eventually reconciled partly by Rutherford, and partly by Bohr's application of quantum theory.

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