Presentation on theme: "Chapter 6: The Periodic Table"— Presentation transcript:
1 Chapter 6: The Periodic Table 6.1: Development of the Modern Periodic Table
2 Antoine Lavoisier Late 1700’s 33 elements (known at time) organized in four categoriesCategoryElements (Old English Names)GasesLight, heat, dephlogisticated air, phlogisticated gas, inflammable airMetalsAntimony, silver, arsenic, bismuth, cobalt, copper, tin, iron, manganese, mercury, molybdena, nickel, gold, platina, lead, tungsten, zincNonmetalsSulphur, phosphorus, pure charcoal, radical muriatique, radical fluorique, radical boraciqueEarthsChalk, magnesia, barote, clay, siliceous earth
3 Lothar Meyer/Dmitri Mendeleev Mid-late 1800’sDemonstrated a connection between atomic mass and elemental propertiesArranged elements with similar chemical properties horizontallyMendeleev is given more credit because he published first
4 Henry MoseleyEarly 1900’sRealized arranging the elements by atomic mass was not the best way – some elements ended up in columns with elements of different propertiesDiscovered atoms have a unique number of protons (the atomic number)Arranged elements in order of increasing atomic number, which resulted in a periodic pattern of properties
5 Modern Periodic Table Groups/Families = vertical columns Periods = horizontal rows
7 Metalloids – along step line (except for Aluminum)
8 Properties of Metals Conduct heat and electricity Malleable (can be hammered into thin sheets)Ductility (can be pulled into wires)Lustrous (shiny) appearanceAlmost all metals are solids at normal temperatures
9 Properties of Non-Metals Generally lack properties that characterize metalsShow more variation in properties than metals doMany are gaseous at normal temperatures
10 Classification of the elements Section 6.2Classification of the elements
11 6.2: Organizing the Elements by Electron Configuration Valence electronsElectrons in the outermost principal energy levelNumber of valence electrons correspond to the representative elements group number (Group 1 has 1 valence electron, Group 2 has 2 valence electrons, Group 13 has 3 because it is the 3rd representative group, etc)Energy level of valence electrons correspond to the period number (Period 4 valence electrons are in the 4th energy level and so on…)
12 The s-, p-, d-, and f-Block Elements We saw these with our little “cheat sheets”This shows which sublevel is being filled
14 PERIODIC TREND QUIZ 1)What group is the: Noble Gases Alkali Metals HalogensTransition Metals2)Identify the # of valence electrons for each group/family.3)An element with an acquired (+) or (-) charge is termed an _____.
15 QUIZ CONT. 4)Identify what groups represent: S block = P block = D block =F block =5) Why do elements “give up” or “take” electrons? Think in terms of outer shell, what is this outer shell called?
16 What are Periodic Trends? Many properties of the elements change in a predictable way, based on their location in the periodic tableWe will look at the following properties:Atomic radiusIonic radiusIonization energy – the energy req’d to remove an electron from a gaseous atomElectronegativity – ability of an atom to attract electrons in a chemical bond
17 Atomic Radius Trends within periods Trends within groups Decrease in atomic radius as you move from left to right across a periodTrends within groupsGeneral increase in atomic radius as you move down a group
18 Ionic RadiusAn ION is an atom or bonded group of atoms that has a positive or negative chargeWhen atoms lose electrons and become positive ions, they always become smallerWhen atoms gain electrons and become negative ions, they become larger
19 Ionic Radius (cont’d) Trends within periods (see Fig 6.14) Generally, as you move from left to right across a period, the size of the positive ions decreaseThen, beginning in group 15 or 16, the size of the much-larger negative ions also gradually decreasesTrends within groupsAs you move down a group, ionic size gradually increases
20 Ionization Energy Trends within periods Trends within groups Values of first ionization energies generally increase as you move from left to right across a period.Trends within groupsFirst ionization energies generally decrease as you move down a group
21 The Octet RuleAtoms tend to gain, lose, or share electrons in order to acquire a full set of eight valence electronsException: Hydrogen does not want 8 valence electrons it will usually give up it’s one electron to make a positive ion
22 Electronegativity Electronegativity values range from 0.7 to 3.98 Fluorine is the most electronegative atom (3.98)Francium is the least electronegative atom (0.70)Many periodic tables list electronegativity values as well
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