Bromine on Periodic Table
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The Development of the Periodic Table and Its Consequences Citation: J
Firenze University Press www.fupress.com/substantia The Development of the Periodic Table and its Consequences Citation: J. Emsley (2019) The Devel- opment of the Periodic Table and its Consequences. Substantia 3(2) Suppl. 5: 15-27. doi: 10.13128/Substantia-297 John Emsley Copyright: © 2019 J. Emsley. This is Alameda Lodge, 23a Alameda Road, Ampthill, MK45 2LA, UK an open access, peer-reviewed article E-mail: [email protected] published by Firenze University Press (http://www.fupress.com/substantia) and distributed under the terms of the Abstract. Chemistry is fortunate among the sciences in having an icon that is instant- Creative Commons Attribution License, ly recognisable around the world: the periodic table. The United Nations has deemed which permits unrestricted use, distri- 2019 to be the International Year of the Periodic Table, in commemoration of the 150th bution, and reproduction in any medi- anniversary of the first paper in which it appeared. That had been written by a Russian um, provided the original author and chemist, Dmitri Mendeleev, and was published in May 1869. Since then, there have source are credited. been many versions of the table, but one format has come to be the most widely used Data Availability Statement: All rel- and is to be seen everywhere. The route to this preferred form of the table makes an evant data are within the paper and its interesting story. Supporting Information files. Keywords. Periodic table, Mendeleev, Newlands, Deming, Seaborg. Competing Interests: The Author(s) declare(s) no conflict of interest. INTRODUCTION There are hundreds of periodic tables but the one that is widely repro- duced has the approval of the International Union of Pure and Applied Chemistry (IUPAC) and is shown in Fig.1. -
Of the Periodic Table
of the Periodic Table teacher notes Give your students a visual introduction to the families of the periodic table! This product includes eight mini- posters, one for each of the element families on the main group of the periodic table: Alkali Metals, Alkaline Earth Metals, Boron/Aluminum Group (Icosagens), Carbon Group (Crystallogens), Nitrogen Group (Pnictogens), Oxygen Group (Chalcogens), Halogens, and Noble Gases. The mini-posters give overview information about the family as well as a visual of where on the periodic table the family is located and a diagram of an atom of that family highlighting the number of valence electrons. Also included is the student packet, which is broken into the eight families and asks for specific information that students will find on the mini-posters. The students are also directed to color each family with a specific color on the blank graphic organizer at the end of their packet and they go to the fantastic interactive table at www.periodictable.com to learn even more about the elements in each family. Furthermore, there is a section for students to conduct their own research on the element of hydrogen, which does not belong to a family. When I use this activity, I print two of each mini-poster in color (pages 8 through 15 of this file), laminate them, and lay them on a big table. I have students work in partners to read about each family, one at a time, and complete that section of the student packet (pages 16 through 21 of this file). When they finish, they bring the mini-poster back to the table for another group to use. -
Periodic Trends in the Main Group Elements
Chemistry of The Main Group Elements 1. Hydrogen Hydrogen is the most abundant element in the universe, but it accounts for less than 1% (by mass) in the Earth’s crust. It is the third most abundant element in the living system. There are three naturally occurring isotopes of hydrogen: hydrogen (1H) - the most abundant isotope, deuterium (2H), and tritium 3 ( H) which is radioactive. Most of hydrogen occurs as H2O, hydrocarbon, and biological compounds. Hydrogen is a colorless gas with m.p. = -259oC (14 K) and b.p. = -253oC (20 K). Hydrogen is placed in Group 1A (1), together with alkali metals, because of its single electron in the valence shell and its common oxidation state of +1. However, it is physically and chemically different from any of the alkali metals. Hydrogen reacts with reactive metals (such as those of Group 1A and 2A) to for metal hydrides, where hydrogen is the anion with a “-1” charge. Because of this hydrogen may also be placed in Group 7A (17) together with the halogens. Like other nonmetals, hydrogen has a relatively high ionization energy (I.E. = 1311 kJ/mol), and its electronegativity is 2.1 (twice as high as those of alkali metals). Reactions of Hydrogen with Reactive Metals to form Salt like Hydrides Hydrogen reacts with reactive metals to form ionic (salt like) hydrides: 2Li(s) + H2(g) 2LiH(s); Ca(s) + H2(g) CaH2(s); The hydrides are very reactive and act as a strong base. It reacts violently with water to produce hydrogen gas: NaH(s) + H2O(l) NaOH(aq) + H2(g); It is also a strong reducing agent and is used to reduce TiCl4 to titanium metal: TiCl4(l) + 4LiH(s) Ti(s) + 4LiCl(s) + 2H2(g) Reactions of Hydrogen with Nonmetals Hydrogen reacts with nonmetals to form covalent compounds such as HF, HCl, HBr, HI, H2O, H2S, NH3, CH4, and other organic and biological compounds. -
Stratospheric Ozone Is Destroyed by Reactions Involving
20 Questions: 2010 Update Section II: THE OZONE DEPLETION PROCESS What are the chlorine and bromine reactions that destroy Q9 stratospheric ozone? Reactive gases containing chlorine and bromine destroy stratospheric ozone in “catalytic” cycles made up of two or more separate reactions. As a result, a single chlorine or bromine atom can destroy many thousands of ozone molecules before it leaves the stratosphere. In this way, a small amount of reactive chlorine or bromine has a large impact on the ozone layer. A special situation develops in polar regions in the late winter/early spring season where large enhancements in the abun- dance of the most reactive gas, chlorine monoxide, leads to severe ozone depletion. tratospheric ozone is destroyed by reactions involving before it happens to react with another gas, breaking the cata- Sreactive halogen gases, which are produced in the chemi- lytic cycle, and up to tens of thousands of ozone molecules cal conversion of halogen source gases (see Figure Q8-1). The during the total time of its stay in the stratosphere. most reactive of these gases are chlorine monoxide (ClO), bro- Polar Cycles 2 and 3. The abundance of ClO is greatly mine monoxide (BrO), and chlorine and bromine atoms (Cl increased in polar regions during winter as a result of reac- and Br). These gases participate in three principal reaction tions on the surfaces of polar stratospheric clouds (PSCs) (see cycles that destroy ozone. Q8 and Q10). Cycles 2 and 3 (see Figure Q9-2) become the Cycle 1. Ozone destruction Cycle 1 is illustrated in Figure dominant reaction mechanisms for polar ozone loss because of Q9-1. -
Interhalogen Compounds
INTERHALOGEN COMPOUNDS Smt. EDNA RICHARD Asst. Professor Department of Chemistry INTERHALOGEN COMPOUND An interhalogen compound is a molecule which contains two or more different halogen atoms (fluorine, chlorine, bromine, iodine, or astatine) and no atoms of elements from any other group. Most interhalogen compounds known are binary (composed of only two distinct elements) The common interhalogen compounds include Chlorine monofluoride, bromine trifluoride, iodine pentafluoride, iodine heptafluoride, etc Interhalogen compounds into four types, depending on the number of atoms in the particle. They are as follows: XY XY3 XY5 XY7 X is the bigger (or) less electronegative halogen. Y represents the smaller (or) more electronegative halogen. Properties of Interhalogen Compounds •We can find Interhalogen compounds in vapour, solid or fluid state. • A lot of these compounds are unstable solids or fluids at 298K. A few other compounds are gases as well. As an example, chlorine monofluoride is a gas. On the other hand, bromine trifluoride and iodine trifluoride are solid and liquid respectively. •These compounds are covalent in nature. •These interhalogen compounds are diamagnetic in nature. This is because they have bond pairs and lone pairs. •Interhalogen compounds are very reactive. One exception to this is fluorine. This is because the A-X bond in interhalogens is much weaker than the X-X bond in halogens, except for the F-F bond. •We can use the VSEPR theory to explain the unique structure of these interhalogens. In chlorine trifluoride, the central atom is that of chlorine. It has seven electrons in its outermost valence shell. Three of these electrons form three bond pairs with three fluorine molecules leaving four electrons. -
Q7 What Emissions from Human Activities Lead to Ozone Depletion?
20 Questions: 2010 Update Section II: THE OZONE DEPLETION PROCESS Q7 What emissions from human activities lead to ozone depletion? Certain industrial processes and consumer products result in the emission of ozone-depleting substances (ODSs) to the atmosphere. ODSs are manufactured halogen source gases that are controlled worldwide by the Montreal Protocol. These gases bring chlorine and bromine atoms to the stratosphere, where they destroy ozone in chemical reactions. Important examples are the chlorofluorocarbons (CFCs), once used in almost all refrigeration and air conditioning systems, and the halons, which were used in fire extinguishers. Current ODS abundances in the atmosphere are known directly from air sample measurements. Halogen source gases versus ODSs. Those halogen activities (see Figure Q7-1). Methyl bromide is used primarily source gases emitted by human activities and controlled by as an agricultural and pre-shipping fumigant. the Montreal Protocol are referred to as ODSs within the Mon- Natural sources of chlorine and bromine. There are a treal Protocol, by the media, and in the scientific literature. few halogen source gases present in the stratosphere that have The Montreal Protocol now controls the global production large natural sources. These include methyl chloride (CH3Cl) and consumption of ODSs (see Q15). Halogen source gases and methyl bromide (CH3Br), both of which are emitted by that have only natural sources are not classified as ODSs. The oceanic and terrestrial ecosystems. Natural sources of these contributions of ODSs and natural halogen source gases to two gases contributed about 17% of the chlorine in the strato- chlorine and bromine entering the stratosphere in 2008 are sphere in 2008 and about 30% of the bromine (see Figure Q7-1). -
Chemistry of the Noble Gases*
CHEMISTRY OF THE NOBLE GASES* By Professor K. K. GREE~woon , :.\I.Sc., sc.D .. r".lU.C. University of N ewca.stle 1tpon Tyne The inert gases, or noble gases as they are elements were unsuccessful, and for over now more appropriately called, are a remark 60 years they epitomized chemical inertness. able group of elements. The lightest, helium, Indeed, their electron configuration, s2p6, was recognized in the gases of the sun before became known as 'the stable octet,' and this it was isolated on ea.rth as its name (i]A.tos) fotmed the basis of the fit·st electronic theory implies. The first inert gas was isolated in of valency in 1916. Despite this, many 1895 by Ramsay and Rayleigh; it was named people felt that it should be possible to induce argon (apy6s, inert) and occurs to the extent the inert gases to form compounds, and many of 0·93% in the earth's atmosphere. The of the early experiments directed to this end other gases were all isolated before the turn have recently been reviewed.l of the century and were named neon (v€ov, There were several reasons why chemists new), krypton (KpVn'TOV, hidden), xenon believed that the inert gases might form ~€vov, stmnger) and radon (radioactive chemical compounds under the correct con emanation). Though they occur much less ditions. For example, the ionization poten abundantly than argon they cannot strictly tial of xenon is actually lower than those of be called rare gases; this can be illustrated hydrogen, nitrogen, oxygen, fl uorine and by calculating the volumes occupied a.t s.t.p. -
The Influence of Nitrogen Oxides on the Activation of Bromide And
Open Access Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Atmos. Chem. Phys. Discuss., 14, 10135–10166, 2014 Atmospheric www.atmos-chem-phys-discuss.net/14/10135/2014/ Chemistry doi:10.5194/acpd-14-10135-2014 © Author(s) 2014. CC Attribution 3.0 License. and Physics Discussions This discussion paper is/has been under review for the journal Atmospheric Chemistry and Physics (ACP). Please refer to the corresponding final paper in ACP if available. The influence of nitrogen oxides on the activation of bromide and chloride in salt aerosol S. Bleicher1, J. C. Buxmann2,*, R. Sander3, T. P. Riedel4, J. A. Thornton4, U. Platt2, and C. Zetzsch1 1Atmospheric Chemistry Research Unit, University of Bayreuth, Bayreuth, Germany 2Institut für Umweltphysik, University of Heidelberg, Heidelberg, Germany 3Air Chemistry Department, Max-Planck Institute for Chemistry, Mainz, Germany 4University of Washington, Seattle, USA *now at: Met Office, Exeter, UK Received: 6 March 2014 – Accepted: 11 March 2014 – Published: 22 April 2014 Correspondence to: C. Zetzsch ([email protected]) Published by Copernicus Publications on behalf of the European Geosciences Union. 10135 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Abstract Experiments on salt aerosol with different salt contents were performed in a Teflon chamber under tropospheric light conditions with various initial contents of nitrogen oxides (NOx = NO + NO2). A strong activation of halogens was found at high NOx 5 mixing ratios, even in samples with lower bromide contents such as road salts. The ozone depletion by reactive halogen species released from the aerosol, was found to be a function of the initial NOx mixing ratio. -
Absolute Isotopic Abundance Ratio and the Atomic Weight of Bromine Edward 1
JOURNAL OF RESEARCH of the National Bureau of Standards-A. Physics and Chemistry Vol. 68A, No.6, November- December 1964 Absolute Isotopic Abundance Ratio and the Atomic Weight of Bromine Edward 1. Catanzaro, Thomas 1. Murphy, Ernest 1. Garner, and William R. Shields (August 4, 1964) An absolute value is obtained f<?r the isotop~c abundance ratio of bromine using ther mal emtSS lon mass spectrometers cahbrated for bws by the use of samples of known isotopic composltwn prepared from nearly pure separated bromine isotopes. The res ultin g absolute 13r 79/13r81 ratI,D, IS 1.02784 ± 0.00190 which yield s an atomic weight (CI2 = 12) of 79.90363 ± 0.0009.2 . I he l.Ildlcated uncertainties are overall limi ts of error based on 95 percent con fid ence lunlts for t he mean and allowances for t he effects of known sources of possible sys tematIC error plus a coml?onent to cover possible natural variations in isotopic composition a lthough no provable varIatwns were noted among t il e 13r 79/13r81 ratios of 29 commercial and naturlll samples. Mass s pectr?metric determinations of the atomic weights of bromine and sil ver gIve a combining weight ratio of Ag13r/Ag = 1.740752. 1. Introduction known isotopic composition, prepared from nearly p~re separated bromine isotopes. The measured .The atomic weights of silver, chlorine, and bro bIases were then used to obtain the absolute Br79/ BrB1 ratio of a reference sample of commercial so mme form the classical basis for establishino . atomic weights of many of the elemen ts. -
Mean Amplitudes of Vibration of Iodine Trifluoride
Note 333 Mean Amplitudes of Vibration of Iodine Table 1. Calculated mean amplitudes of vibration (in A) of IF3. Trifluoride HK) MI-F(ax) «I-F(eq) u F(ax)...F(ax) MF(ax)...F(eq) E. J. Baran 0 0.0448 0.0401 0.057 0.057 Centro de Qufmica Inorgänica (CEQUINOR/CONICET, 100 0.0448 0.0401 0.057 0.058 UNLP), Facultad de Ciencias Exactas, 200 0.0460 0.0405 0.058 0.062 Universidad Nacional de La Plata, C. Correo 962, 298.16 0.0489 0.0420 0.061 0.068 1900-La Plata, Argentina 300 0.0489 0.0420 0.061 0.068 400 0.0528 0.0444 0.066 0.075 Reprint requests to Prof. E. J. B.; 500 0.0568 0.0474 0.071 0.082 E-mail: [email protected] 600 0.0609 0.0500 0.075 0.089 700 0.0648 0.0529 0.080 0.095 Z. Naturforsch. 56a, 333-334 (2001); 800 0.0686 0.0558 0.085 0.101 received January 12, 2001 900 0.0723 0.0586 0.089 0.107 1000 0.0759 0.0613 0.094 0.113 Mean amplitudes of vibration of IF3 have been calculated from vibrational spectroscopic data in the temperature range between 0 and 1000 K. Bond properties of the molecule are dis cussed on the basis of these results. Some comparison with relat Table 2. Comparison of the mean amplitudes of vibration (in A ed species are made. and at 298. 16 K) of the three isostructural XF3 species. -
1 Unit 4.4 Chemistry of Non-Transition Elements Few Facts of Halogens: A
Unit 4.4 Chemistry of Non-transition Elements Few facts of halogens: a) Ionisation energy of halogens is very high. This indicates that it has very little tendency to lose electrons. Due to gradual increase in size, it decreases down the group. b) The halogen molecules are held by weak Vander Waals forces, which increase down the group. This is responsible for the solid state of iodine. c) Chlorine has highest electron affinity in the group. Due to small size, fluorine has lower electron affinity than chlorine. d) All halogens are coloured as shown below: Halogens Fluorine Chlorine Bromine Iodine Colour Light Yellow Greenish Yellow Reddish Yellow Dark Violet The origin of colours of halogens is due to the absorption of visible light which excite the outermost electron to a higher energy level. Fluorine, being very small in size require very large excitation energy (obtained from the blue or violet part) of light, hence light yellow. Iodine being very large in size, the required lower excitation energy is obtained by absorption of yellow part of light. Interhalogen compounds: Halogen elements have different electro-negativity. Due to this they combine with each other to form covalent compounds (binary). “The binary compounds formed by halogens amongst themselves are known as Inter- halogen compounds”. These compounds have general formula; XYn, where n = 1, 3, 5 & 7. Ternary compounds of halogens are not known; as such a complex molecule might be unstable. Classification: Various types of inter-halogen compounds are tabulated below: Element Fluorine Chlorine Bromine Iodine Fluorine ------ ----- ----- ----- Chlorine ClF, ClF3, ClF5 --- --- --- Bromine BrF, BrF3, BrF5 BrCl --- --- Iodine IF, IF3, IF5, IF7 ICl, ICl3 IBr --- From the above table, the following points may be noted: • The inter-halogen compounds may be regarded as the halide of the more electronegative halogen. -
5.04 Principles of Inorganic Chemistry II Fall 2008
MIT OpenCourseWare http://ocw.mit.edu 5.04 Principles of Inorganic Chemistry II Fall 2008 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms. Chemistry 5.04 (F08) Practice Problem Set Practice vibrational and MO problems for the exam 1. Chatt prepared the dinitrogen complexes, trans-Mo(N2)2(PR3)4 in which the surprising result of two π-acid ligands coordinate trans to each other. Build the MO diagram for the complex. Draw the frontier d-orbital MOs and indicate the HOMO and LUMO orbitals. 2. Shown below are two electronically different metal carbides. Use MO arguments to address the following: a. Draw the HOMO for each complex. b. Explain the vacant site trans to the carbide atom in the square pyramidal, Ru complex. c. How many pi electrons are donated from the anilides into the metal in the moly complex (assume that for each sp2 hybirdized N-atom the tert-butly group point up, towards the apical carbide, and the aryl groups point down). Do the anilides and carbide compete for π symmetry orbitals on moly? d. Estimate the relative acidity of both carbide-carbon atoms. Which of these acids will protonate the carbide: MeC6H5, HCPh3, H3CCOOH, H(OEt2)B[3,5-C6H3(CF3)2] (answer yes or no for each acid/carbide combination)? 8 3. The synthesis of uranocene, [(η -C8H8)2U], is considered as the beginning of modern organoactinide chemistry. Organoactinides are distinguished by covalent interactions between the 5f orbitals of the 2– actinoids as well as the 6d orbitals.