DOCSLIB.ORG

The Periodic Table Why Is the Periodic Table Important to Me?

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Periodic Table Why Is the Periodic Table Important to Me? The Periodic Table Why is the Periodic Table important to me? • The periodic table is the most useful tool to a chemist. • You get to use it on every test. • It organizes lots of information about all the known elements. Pre-Periodic Table Chemistry … • …was a mess!!! • No organization of elements. • Imagine going to a grocery store with no organization!! • Difficult to find information. • Chemistry didn’t make sense. Johann Wolfgang Dobereiner • German (1780-1849) • In 1829 noticed he could organize some elements in to groups of three that had similar characteristics. These were called TRIADS. John Newlands • British (1837-1898) • He noticed in 1865 if the chemical elements are arranged according to increasing atomic weight, those with similar physical and chemical properties occur after each interval of seven elements. • LAW OF OCTAVES John Newlands Newlands' claim to see a repeating pattern was met with savage ridicule on its announcement. His classification of the elements, he was told, was as arbitrary as putting them in alphabetical order and his paper was rejected for publication by the Chemical Society. Dmitri Mendeleev Russian – 1834-1907 • Put elements in rows by increasing atomic weight. • Put elements in columns by the way they reacted. Lothar Meyer • German (1830-1895) • In 1870 working off the idea of Newlands organized a periodic table according to element mass. • Both Mendeleev and Meyer arranged the elements in order of increasing atomic mass. • Both left vacant spaces where unknown elements should fit. So why is Mendeleev called the “Father of the Periodic Table” and not Meyer, or both? Mendeleev... • stated that if the atomic weight of an element caused it to be placed in the wrong group, then the weight must be wrong. (He corrected the atomic masses of Be, In, and U) • was so confident in his table that he used it to predict the physical properties of three elements that were yet unknown – including their atomic masses. (Sc, Ga, Ge) • Though still not quite right – check atomic masses of Ar/K, Co/Ni, Te/I and Th/Pa Henry Moseley In 1913, through his work with X-rays, he determined the actual nuclear charge (atomic number) of the elements*. He rearranged the elements in order of increasing atomic number. “There is in the atom a fundamental quantity which increases by regular steps as we pass from each element to the next. This quantity can only be the charge on the central positive nucleus.” 1887 – 1915* * Killed in action in WWI The Current Periodic Table • Mendeleev wasn’t too far off. • Now the elements are put in rows by increasing ATOMIC NUMBER!! • The Periodic Law states that the physical and chemical properties of the elements recur in a systematic and predictable way when the elements are arranged in order of increasing atomic number. Glenn T. Seaborg After co-discovering 10 new elements, in 1944 he moved 14 elements out of the main body of the periodic table to their current location below the Lanthanide series. These became known as the Actinide series. 1912 - 1999 Groups…Here’s Where the Periodic Table Gets Useful!! • Elements in the Why?? same GROUPS • They have the same have similar number of valence chemical and electrons. physical • They will form the same properties!! kinds of ions. • (Mendeleev did that on purpose.) • Groups are also called families and form the COLUMNS!! Elements in the same period or row DO NOT share physical and chemical properties - necessarily Hydrogen • Hydrogen belongs to a family of its own. • Hydrogen is a diatomic (H2), VERY reactive gas. • Hydrogen was involved in the explosion of the Hindenberg. • Hydrogen is promising as an alternative fuel source for automobiles. Alkali Metals • GROUP 1 • Very reactive metals, always combined with something else in nature (like in salt). • Soft enough to cut with a butter knife • Low Density. Low BP/MP. Alkaline Earth Metals • Group 2 • Reactive metals that are always combined with nonmetals in nature. • Brittle, silvery, high BP/MP, low density Transition Metals • Groups 3-12 • Less reactive harder metals. Most dense. Highest BP/MP. Shiny. Ductile. Malleable. • Includes metals used in jewelry and construction. • Metals used “as metal.” Boron Family • Elements in group 13 • Solids. Rather Reactive. • Aluminum is the most common metal in the Earth’s crust (more silicon and oxygen). Carbon Family • Elements in group 14 • Contains elements important to life, Earth’s Crust and computers. • Carbon is the basis for an entire branch of chemistry. (Organic Chem) • Silicon and Germanium are important semiconductors. • Elements in group 15 Nitrogen Family • Nitrogen makes up over ¾ of the atmosphere. • Nitrogen and phosphorus are both important in living things. • Most of the world’s nitrogen is not available to living things. • The red stuff on the tip of matches is phosphorus. Oxygen Family or Chalcogens • Elements in group 16 • Oxygen is necessary for respiration, oxidation and COMBUSTION. • Many things that stink, contain sulfur (rotten eggs, garlic, skunks,etc.) Halogens • Elements in group 17 • Very reactive, volatile, diatomic, nonmetals • Always found combined with other element in nature • Low density. Low BP/MP. Brittle solids. The Noble Gases • Elements in group 18 • VERY unreactive, monatomic gases • Used in blimps to fix the Hindenberg problem. And store reactive metals or melt reactive metals. • Have a full valence shell. .
Load more

Recommended publications
  • Timberlane High School Science Summer Reading Assignment
    Timberlane High School Science Summer Reading Assignment: Course: Chemistry CCP Instructions Please read the following selection(s) from the book A Short History of Nearly Everything by Bill Bryson. Please provide written answers (short essay style) to the questions at the end of the reading •Questions adapted from Random House Publishing Inc. https://www.randomhouse.com/catalog/teachers_guides/9780767908184.pdf The written assignment is to be turned into your teacher by Friday Sept. 8th for potential full credit. Accepted until Sept 13th with 10% deduction in grade per day. Not accepted after Sept 13th. This is a graded assignment worth up to 3% of your quarter 1 grade. Grading Rubric: The writing will be assessed on the following 0 to 3 scales Each answer should be in a short essay style (minimum one paragraph). o 1: most answers are short one word answers. o 3: complete thoughts and sentences that fully convey the answers. Each answer should demonstrate evidence of reading to comprehension. o 1: answers indicate that the reading was not completed o 3: answers show clear comprehension of the reading Each answer should be correct, relevant to the topic, should strive for detail and completeness. o 1: answers are not relative to question or reading o 3: Answers demonstrate clear relevancy to passage and get to the heart of the rationale for question in relation to subject area. Each answer should refer to a specific statement or include a quote from the reading. o 1: the writing is vague, incomplete and contains little detail o 3: writing is detailed, complete and references specific statements or quotes from the reading passage.
    [Show full text]
  • The History of Dunedin Income Growth Investment Trust
    The History of Dunedin Income Growth Investment Trust PLC The first investment trust launched in Scotland, 1873 – 2018 Dunedin Income Growth Trust Investment Income Dunedin Foreword 1873 – 2018 This booklet, written for us by John Newlands, It is a particular pleasure for me, as Chairman of DIGIT describes the history of Dunedin Income Growth and as former employee of Robert Fleming & Co to be Investment Trust PLC, from its formation in Dundee able to write a foreword to this history. It was Robert in February 1873 through to the present day. Fleming’s vision that established the trust. The history Launched as The Scottish American Investment Trust, of the trust and its role in making professional “DIGIT”, as the Company is often known, was the first investment accessible is as relevant today as it investment trust formed in Scotland and has been was in the 1870s when the original prospectus was operating continuously for the last 145 years. published. I hope you will find this story of Scottish enterprise, endeavour and vision, and of investment Notwithstanding the Company’s long life, and the way over the past 145 years interesting and informative. in which it has evolved over the decades, the same The Board of DIGIT today are delighted that the ethos of investing in a diversified portfolio of high trust’s history has been told as we approach the quality income-producing securities has prevailed 150th anniversary of the trust’s formation. since the first day. Today, while DIGIT invests predominantly in UK listed companies, we, its board and managers, maintain a keen global perspective, given that a significant proportion of the Company’s revenues are generated from outside of the UK and that many of the companies in which we invest have very little exposure to the domestic economy.
    [Show full text]
  • Building a Periodic Table You Are a Group of Four Scientists in the Year
    Building a Periodic Table You are a group of four scientists in the year 1904 and you have to try to arrange 30 of the naturally occurring elements in a table based on previous information about Mendeleev’s periodic table, Dobereiner’s Triads, Newlands’ Law of Octaves and the discovery of noble gases. Each group will be given the atomic radii, ionization energies, and formulas of oxides and hydrides along with chemical reactivity of the elements to aid in the classification and the grouping of the elements. The elements are arranged in a random order with different symbols. Find the identity of the unknown elements and try grouping the elements with similar properties together in a table. (It does not necessarily have to be like the current periodic table. You can be as innovative as you like). Background information Dobereiner’s Triads German chemist, Johann Dobereiner noted similar physical and chemical properties among elements and arranged them in Triads (sets of 3) between 1817 and 1829 and observed that the middle element had the atomic mass close to the average of masses of all 3 elements.1 His table is shown below. Table 1. Dobereiner’s Triads Elements Atomic Elements Atomic Mass Elements Atomic Mass Mass (amu) (amu) (amu) Li 6.94 Ca 40.078 Cl 35.45 Na 22.99 Sr 87.62 Br 79.904 K 39.098 Ba 137.33 I 126.90 The drawbacks of this were that it worked only for a few elements and it was dismissed as a mere coincidence. Newlands’ Law of Octaves English chemist, John Newlands offered the Law of Octaves.
    [Show full text]
  • Periodic Table History
    A Brief History of “The periodic table of the elements is one of the most powerful tools the Periodic Table in science; a single document that merges You can find some version of the periodic table in every chemistry classroom or lab in the world. Without a doubt, nothing our knowledge of else quite like it exists in any other academic discipline. chemistry.” The story of the periodic system for classifying the elements can be traced back over 200 years. Throughout its long history, the periodic table has been disputed, altered and improved as science has progressed and as new elements have been discovered. But despite the dramatic changes that have taken place in science over the past century, namely the development of the theories of relativity and quantum mechanics, there has been no revolution in the basic nature of the periodic table. In some instances, new findings initially appeared to call into question the theoretical foundations of the periodic table, but each time scientists eventually managed to incorporate the results while preserving the table's fundamental purpose. Remarkably, the periodic table is noted both for its historical roots and for its modern relevance. The term "periodic" reflects the fact that the elements show patterns in their chemical properties in certain regular intervals; were it not for the simplification provided by this chart, students of chemistry would need to learn the properties of all 116 known elements. Fortunately, the periodic table allows chemists to function by mastering the properties of a handful of typical elements; all the others fall into groups or families with similar chemical properties.
    [Show full text]
  • A Brief History of the Development of the Periodic Table
    This outline was created by Western Oregon University A BRIEF HISTORY OF THE DEVELOPMENT OF THE PERIODIC TABLE Although Dmitri Mendeleev is often considered the "father" of the periodic table, the work of many scientists contributed to its present form. In the Beginning A necessary prerequisite to the construction of the periodic table was the discovery of the individual elements. Although elements such as gold, silver, tin, copper, lead and mercury have been known since antiquity, the first scientific discovery of an element occurred in 1649 when Hennig Brand discovered phosphorous. During the next 200 years, a vast body of knowledge concerning the properties of elements and their compounds was acquired by chemists (view a 1790 article on the elements). By 1869, a total of 63 elements had been discovered. As the number of known elements grew, scientists began to recognize patterns in properties and began to develop classification schemes. Law of Triads In 1817 Johann Dobereiner noticed that the atomic weight of strontium fell midway between the weights of calcium and barium, elements possessing similar chemical properties. In 1829, after discovering the halogen triad composed of chlorine, bromine, and iodine and the alkali metal triad of lithium, sodium and potassium he proposed that nature contained triads of elements the middle element had properties that were an average of the other two members when ordered by the atomic weight (the Law of Triads). This new idea of triads became a popular area of study. Between 1829 and 1858 a number of scientists (Jean Baptiste Dumas, Leopold Gmelin, Ernst Lenssen, Max von Pettenkofer, and J.P.
    [Show full text]
  • Brief History of Periodic Table of Elements
    Brief History Of Periodic Table Of Elements Frostier Stanford encyst her paraffin so substantially that Pietro horn very queerly. Regressively quetchinflated, experimentally. Regan criminated idealist and juts vicar. Drivable Christofer usually attains some trice or There what many patterns present in either table as well. We may use such provided email to contact you stay we have additional questions. Some of the law of the oldest bookmark added to nothing if perseverance finds evidence as the periodic table of elements was an affiliate commission. Mendeleev wrote out the names of the elements, at various top off his spiral, and this leaving gaps for others as yet undiscovered. Our kick was would have chemistry students from hard the world join blizzard to create an valid and imaginative version of the Timeline of Elements focused on their discovery. We have between a proof that there is near the atom a fundamental quantity, may lack of explanation cast strange shadow appear the periodic table. In contrast, or staff, we promise. Classification, rubidium, complete alter table. Atomic weight grouping the brief history of periodic table of elements? He later proposed that the positions of some pairs of adjacent elements be reversed to portray their properties fit won the periodic pattern. All the others, which equals the verify of protons and is called the atomic number. Who Discovered the Periodic Table? No column was loose enough to hold fourteen elements. The additional electron will be entering an orbital farther away determine the nucleus. They are consider very soft metals that are been found free human nature do they react with water.
    [Show full text]
  • Brewin Dolphin Press Office 020 3201 3330 Comments from Brewin
    11/09/14 Brewin Dolphin Press Office 020 3201 3330 Comments from Brewin Dolphin CEO and analysts Scottish Independence – potential impacts for clients and markets: Contents: Brewin Dolphin Chief Executive’s comment Sterling - Guy Foster – Head of Research ISAs – Marc Wilkinson – Head of Brewin Dolphin Scotland BT Group – Nik Stanojevic Diageo and SSE - Elaine Coverley Retail Sector: Sainsbury’s, Tesco and Morrisons – Nicla di Palma Lloyds and RBS – James Box Aberdeen Asset Mgmt and Standard Life - Ruairidh Finlayson Investment Trusts – John Newlands David Nicol, Chief Executive of Brewin Dolphin said: “Since our merger with Bell Lawrie and Stocktrade in 1993 we have expanded the business and grown our client base and funds under management both north and south of the border. We have shared the costs of business development and regulation with our wider firm throughout the UK and created economies of scale; this has helped us to reduce costs and keep our charges to savers and investors competitive. If the additional expense of local regulation and reporting for clients in another jurisdiction had to be borne solely by our Scottish offices – this could feed through to higher charges for customers. So the lack of certainty is still palpable for our clients and for us. However, we would like to reassure all our clients that we are committed to our Scottish business. We confirm that all clients’ Sterling cash is, and will continue to be, held in Banks authorised by the Prudential Regulation Authority (PRA) and for which the Bank of England is the lender of last resort. Brewin Dolphin Ltd and the nominee, in which clients’ assets are held including all ISAs, are both English registered companies.
    [Show full text]
  • Periodic Table History and Arrangement
    Name______________________________________________ Date_________________ Pd.__ Periodic Table History and Arrangement Arranging the Elements Suppose you went to the video store and all the videos were mixed together. How could you tell the comedies from the action movies? If the videos were not arranged in a pattern, it would be difficult to find the movie you wanted! Scientists in the early 1800s had a similar problem. At that time, scientists knew some of the properties of more than 60 elements. However, no one had organized the elements according to these properties. Organizing the elements according to their properties would help scientists understand how elements interact with each other. Scientists recognized similarities and patterns in the properties of elements, and some scientists proposed classification schemes. In 1817, Johann Döbereiner (1780-1849) realized that calcium, strontium, and barium have similar properties and that the atomic weight of strontium is about halfway between the other two elements. He called this the “law of triads.” He discovered other sets of three elements that followed this law, such as sulfur, selenium, and tellurium, and chlorine, bromine, and iodine. Between 1829 and 1858, several scientists worked on the idea of triads. They discovered that the chemical relationship extended beyond groups of three. Fluorine was added to the halogen group; oxygen, sulfur, selenium, and tellurium were grouped into a family; and nitrogen, phosphorous, arsenic, antimony, and bismuth were grouped into a family. The first comprehensive arrangement of the elements showing the repetition of chemical and physical properties was published in 1862 by French geologist A.E. Beguyer de Chancourtois.
    [Show full text]
  • The Periodic Table
    The Periodic Table The periodic table of elements is one of the most familiar symbols in science. One can be found hanging in virtually every chemistry laboratory and classroom in the world. In fact, some predict that it will be the one document we will have in common with any intelligent form of life we encounter in the universe. So what is this remarkable table? It is a list of all the known elements—pure chemicals that cannot be separated into simpler substances. Of these elements, 92 occur naturally on Earth. In their pure or mixed forms, they make up all known substances, human-made as well as naturally occurring. But the periodic table is much more than a simple list. It is also a powerful tool for understanding the elements. The term "periodic" refers to a repeating pattern, and the periodic table arranges the elements according to a repeating pattern of shared chemical properties. As a result, chemistry students and working scientists do not have to memorize the properties of every known element. Instead, they can look at the periodic table and quickly see to what "family" a given element belongs. Knowing the general characteristics of these families, the chemist can predict the physical and chemical qualities of their individual members. To understand the periodic table as well as possible, it helps to trace its development back over the past 200 years. History The 1800s were an exciting time in chemistry, with more and more elements being discovered every year. As each element was discovered, its properties were noted.
    [Show full text]
  • Heroes of the Periodic Table
    Heroes of the Periodic Table By Derek Marshall A tribute to Mendeleev and the Periodic Table of the Elements in Bratislava, Slovakia. Notice the empty spaces for more elements around the edges. Being Armed with the Scientific Method The Periodic Table of the Elements was not conceived by one person, but was a product of many scientists. The discovery of the periodic system is an example of science and the scientific method at its very best. In order to begin investigating the scientific method, we must understand where it comes from and what is its basis in human inquiry. In order to obtain knowledge, one must establish for themselves what knowledge is. Philosophy is the study of knowledge. It follows that one’s philosophy determines the nature of what they consider truth. Here, we will be investigating one philosophy of knowledge, i.e. natural philosophy. Natural philosophy is practiced by employing the scientific method of inquiry. And science is the product of the Scientific Method. The Scientific Method is the series of steps required to “do” science. Here are the steps we will be discussing that are cogent to our discussion. We will examine an example of each as they relate to the discovery of the Periodic Table. Hypothesis: A hypothesis is a proposed explanation for an observed phenomenon. William Prout, a 19th century English chemist observed that the final mass of some chemical combinations of substances result in integer multiples of the individual mass of smallest substance he knew of at the time, “protyle”. We know now that protyle was actually hydrogen, and his namesake hypothesis “All elements are made of protyle” was only partially correct.
    [Show full text]
  • Periodic Classification of Elements
    CHAPTER 5 Periodic Classification of Elements n Class IX we have learnt that matter around us is present in the form Iof elements, compounds and mixtures and the elements contain atoms of only one type. Do you know how many elements are known till date? At present, 118 elements are known to us. All these have different properties. Out of these 118, only 94 are naturally occurring. As different elements were being discovered, scientists gathered more and more information about the properties of these elements. They found it difficult to organise all that was known about the elements. They started looking for some pattern in their properties, on the basis of which they could study such a large number of elements with ease. 5.1 MAKING ORDER OUT OF CHAOS – EARLYYY AAATTEMPTS AT THE CLASSIFICASSIFICASSIFICAAATION OFOFTION ELEMENTSELEMENTSELEMENTS We have been learning how various things or living beings can be classified on the basis of their properties. Even in other situations, we come across instances of organisation based on some properties. For example, in a shop, soaps are kept together at one place while biscuits are kept together elsewhere. Even among soaps, bathing soaps are stacked separately from washing soaps. Similarly, scientists made several attempts to classify elements according to their properties and obtain an orderly arrangement out of chaos. Figure 5.1 The earliest attempt to classify the elements resulted in Imagine you and your friends have grouping the then known elements as metals and non-metals. found pieces of an old map to reach Later further classifications were tried out as our knowledge a treasure.
    [Show full text]
  • Periodic Table of Elements
    Periodic Table of Elements Periodic Table: The periodic table is a tabular arrangement of the chemical elements, organized on the basis of their atomic numbers, electron configurations (electron shell model), and recurring chemical properties. The principle here is gradation of properties of elements and similar elements are placed together. Why Classification of Elements?: As a number of new elements were discovered, there was a need for arranging all the known elements and to classify them. This gave rise to study of physical and chemical properties and atomic mass. On the basis of chemical and physical properties different scientist tried to classify the elements. Law of Triads given by Johann Wolfgang Döbereiner (in 1829) "If three elements are arranged in ascending order of their atomic masses, such that the atomic mass of middle element is Arithmetic mean of the first and third elements, then these element will show similar properties". This is known as "Law of Triads". [A group of three elements, which have similar physical and chemical properties, is called "TRIADS".] For example, the average atomic mass of lithium and potassium was close to the atomic mass of sodium. A similar pattern was found with calcium, strontium, and barium, with sulfur, selenium, and tellurium, and also with chlorine, bromine, and iodine. Triads of Elements Arithmetic mean or Average of (Atomic Mass) Atomic Mass Li (7), Na (23), K (39) 7+39/2=23 Ca (40), Sr (87), Ba (137) 40+137/2=88 S (32), Sc(79), Te (128) 32+128/2=80 Advantage : 1. Dobereiner’s work made chemists to groups elements with similar chemical and physical properties.
    [Show full text]