Transcript Slide 1
1790’s French chemist Antoine-Laurent Lavoisier made the first periodic table. 1803- John Dalton improved the periodic table by assigning symbols and masses to each element. 1869- Dimitri Mendeleev, a Russian chemist, arranged the 63 known element at the time, into groups based on their chemical properties and atomic weights. 1912- Henry Moseley, an English physicist improved Mendeleev’s table by listing the elements by their atomic number. Glenn Seaborg- 1930's The heaviest elements were being put up in the body of the periodic table, and Glenn Seaborg "plucked those out" , naming them the Actinide series, which later permitted proper placement of subsequently 'created' elements - the Transactinides, changing the periodic table yet again. How to Name an Element In 2006, element 111 received its official name, Roentgenium. The element's square on the periodic table was unveiled by German science minister Annette Schavan. How to Name an Element Periodic Law When elements on the periodic table are arranged by atomic number, relationships and similarities in properties can be seen. This means that when the elements from the periodic table are arranged in a certain way from lowest to highest atomic number (the number of protons), the ones near each other will have similar properties! The_Periodic_Table.asf Elements fall into three groups characterized by similar properties. metals, nonmetals, and metalloids METALS: majority of elements…where on the periodic table??? Shiny luster Good conductors of heat and electricity Solid at room temperature Malleable, or can be shaped Ductile, or can be drawn into wires without breaking Three or fewer outer electrons 3/4 of all elements are metals Most metals have one, two or three electrons in their outer shell During chemical reactions, metal atoms lose their outer electrons to other atoms, usually, non metals. The outer electrons are far from the positive pull of the protons, thus held loosely in place. A metal atom becomes stable, or nonreactive, when it has lost its outer electron. NONMETALS how many elements and where on the periodic table??? Dull in appearance Poor conductors of heat and electricity Many are gases at room temperature Brittle, cannot change shape without breaking 96% of the human body is made up of nonmetals have five or more outer electrons METALLOIDS: how many elements and where on the periodic table??? Have characteristics of both metals and nonmetals Do not conduct heat and electricity as well as metals All are solids at room temperature Read articles on line..... The Periodic Table I. History A. Lavoisier, Dalton B. Mendeleev, Meyer C. Rutherford, Moseley D. Seaborg II. Metals, Nonmetals, Metalloids III. Organization A. Periods B. Groups C. Group names and info A Short History of the Periodic Table Click here for more great information on th Periodic Table Metals, Nonmetals and Metalloids Today’s periodic table: arranged by atomic number groups-columns of elements having similar chemical properties periods-in order of atomic number, increase across the period or row Periodic Table Elements as Building Blocks As you probably saw, the periodic table is organized like a big grid. The elements are placed in specific locations because of the way they look and act. The periodic table has rows and columns, and they each mean something different. Did ya notice the periodic table sort of looks like a calendar? When you look at a periodic table, each of the rows is considered to be a different period (Get it? Like PERIODic table.). In the periodic table, elements have something in common if they are in the same row. All of the elements in a period have the same number of atomic orbitals. Number of orbitals or energy shells equals the number of the period. All elements in period 2 have two orbitals or energy shells. Period 6 elements have six energy shells. Group Information on the Periodic Table What do elements in the same group have in common? They all have the same number of electrons in the outer shell and thus react similarly. (Valence electrons) For example, all the group 1 (Alkali metals) elements react violently with water. The periodic table groups are as follows (in the brackets are shown the old systems: European and American): Group 1 (IA,IA): the Alkali metals Group 2 (IIA,IIA): the Alkaline earth metals Group 3 (IIIA,IIIB) Group 4 (IVA,IVAB) Group 5 Group 6 Group 7 Group 8 Group 9 Group 10 Group 11 Group 12 (IIB,IIB) Group 13 (IIIB,IIIA): the Boron Group Group 14 (IVB,IVA): the Carbon Group Group 15 (VB,VA): Nitrogen Group Group 16 (VIB,VIA): the Chalcogens Group 17 (VIIB,VIIA): the Halogens Group 18 (Group 0): the Noble gases Group 1: The alkali metals are lithium, sodium, potassium, rubidium, cesium, and francium. Hydrogen is also part of this group, but is only in a metal state at great depths within Jupiter, the pressure is so great that the hydrogen atoms are broken up and the electrons are freed so that the resulting atoms consist of bare protons. This produces a state in which the hydrogen becomes metallic. Alkali Metal Properties Lower densities than other metals One loosely bound valence electron Largest atomic radii in their periods Low ionization energies Low electronegativities Highly reactive when in contact with water Group 2: The alkaline earth metals All the elements are all metals with a shiny, silvery- white color. They are all soft, low density metals, which react readily with halgens to form ionic salts, and with water but not as rapidly as the alkaline metals. For example, sodium and potassium react with room temperature water, however, magnesium reacts only with steam and calcium reacts only with hot water. The elements have two electrons in their valance, or outermost shell. 38 elements in groups 3 through 12 of the periodic table are called "transition metals". As with all metals, the transition elements are both ductile and malleable, and conduct electricity and heat. The interesting thing about transition metals is that their valence electrons, or the electrons they use to combine with other elements, are present in more than one shell. There are three noteworthy elements in the transition metals family. These elements are iron, cobalt, and nickel, and they are the only elements known to produce a magnetic field. The Boron Group, Group 13 Except for boron itself, which is a nonmetal, the elements of group IIIA, or Group 13, are metals (aluminum, gallium, indium, thallium). Even boron in its elemental state is a hard gray material that might be mistaken for a metal. The elements of group IIIA have a valence (number of bonds to atoms other elements) of three. As a group, the elements of the boron group decrease in electronegativity as one goes down the column. Group 14: The Carbon Group has the elements change from nonmetallic in character at the top of the Group to metallic at the bottom. Carbon is a non-metal, silicon and germanium are metalloids, and tin and lead are typical metals. Diamond has a very high refractive index, also the hardest natural substance known and so is important industrially. Silicon is a semi-conductor and just a few millimeters square, have revolutionized the computer and microprocessor industries. Tin and lead, as typical metals, are good conductors of electricity. Group 15: Nitrogen Group includes nitrogen, phosphorus, arsenic, antimony and bismuth and ununpentium. The name pnictogens is also sometimes used for this group; it is not approved by IUPAC . The spelling pnicogen is also recorded. Both spellings derive from the Greek πνίγειν (pnigein), to choke or stifle, which is a property of nitrogen. The chalcogens are the name for the periodic table group 16. It consists of the elements oxygen (O), sulfur (S), selenium (Se), tellurium (Te), the radioactive polonium (Po), and the synthetic ununhexium (Uuh). Oxygen and sulfur are nonmetals, polonium is a true metal, and selenium and tellurium are metalloid semiconductors. Group 17: the halogens are a chemical series including: fluorine , chlorine, bromine, iodine, and astatine. The word comes from Greek roots meaning "salt" and "creator". Group 18: the noble gases are a chemical series which include the elements helium , neon , argon , krypton , xenon and radon . The term noble gas comes from the fact that, just like the common view of human nobility, these gases generally sit around not doing anything, and avoid reacting with 'common' elements. The noble gases were previously referred to as inert gases, but this term is not strictly accurate now that some have been shown to take part in chemical reactions. Attachments The_Periodic_Table.asf