2 Definition What does PERIODIC mean? A repeating patternMendeleev left some spaces in his table because not all elements lined up according to atomic mass. He used info he knew about surrounding elements to PREDICT properties and masses of unknown elements.How about that!
3 Mendeleev (1869) Organized table by... ATOMIC MASSThought pattern must exist between all elementsElements in columns show similar properties…Both physical and chemical!Predicted properties of “missing” elements
4 Moseley (c. 1914) rearranged table by ... ATOMIC NUMBERDetermined atomic number of elements by determining number of protons in element
5 Seaborg (1944) Rearranged Periodic Table with... Lanthanide and Actinide Series pulled out/separated from main Periodic TableDiscovered countless isotopes & 10 new elements
6 Information from Periodic Table Atomic numberChemical symbolAtomic massChemical namePlus countless other information, depending on the table used!
7 Columns of Table = groups or families Newer designation: 1-188 main families labeled with Roman Numeral and letter ‘A’Elements within the same family have similar but not identical propertiesElectron configuration varies periodically (pattern of valence electrons)family #or IA-IIA-IIIA-IVA-VA-VIA-VIIA-VIIIAvalence e
9 Definition Valence electrons electrons found in the outermost energy leveluse the group number to determine number of valence electrons
10 Names of Families Group 1 or IA Group 2 or IIA Group13 or IIIA Group 14 or IVAGroup 15 or VAGroup 16 or VIAGroup 17 or VIIAGroup 18 or VIIIAGroups 3-12Lanthanide & Actinide seriesAlkali metalsAlkaline Earth metalsBoron familyCarbon familyNitrogen familyChalogensHalogensNoble gasesTransition metalsInner transition metals
11 Rows of Table = periods Properties are not alike within a period 7 periods = number of energy levels in atom2 additional rows at bottom of table are Lanthanide and Actinide series and belong to periods 6 and 7
13 Trends Valence number Charge of ion Tendency to gain or lose electrons Atomic size (radius)Ionization energyElectron affinityElectronegativityReactivityMetallic vs. nonmetallic properties
14 Periodic Law Octet Rule The physical and chemical properties of the elements are periodic functions of their atomic number.The tendency of atoms to gain or lose electrons so they acquire 8 electrons in their outer energy level for stability
15 Ionization Energy Electron Affinity energy required to remove an electron from an atom; to form a cationkJ/molattraction of an atom for an added electron; to form an anionkJ/mol
16 Atomic Radius Electro-negativity estimate of the size of an atom distance between the nucleus and the likely location of electron cloudability of an atom to compete with other atoms for electrons shared between themi.e. who wants them more?
17 Across a Period radius decreases ionization energy increases electronegativity increasesb/cnumber of protons increases, as does number of electrons…number of valence electrons increases…so EMF increases…so valence electrons held more tightly…
25 Alkaline Earth Metals Lab An element that is highly reactive tends to gain or lose electrons very easily.A precipitate is an insoluble solid formed as a result of a chemical reaction.In this lab, magnesium formed the least number of precipitates, while barium formed the greatest number of precipitates.Why do you think reactivity increases down a family???
26 REGIONS OF THE TABLEOne more!NONMETALSMETALLOIDSMETALS
27 Metals Found to LEFT of zigzag line on table Good conductors of heat & electricityMalleable (can hammer into thin sheet without breaking)Ductile (can pull into thin wire without breaking)High melting & boiling pointsShiny in lusterTend to lose electrons
28 Nonmetals Found to RIGHT of zigzag line on table Poor conductors of heat & electricityBrittle when solid (break irregularly)Dull in lusterLow melting & boiling pointsTend to gain electrons
29 Metalloids aka Semi-Metals Found along both sides of zigzag line, with exception of Al and PoProperties of both metals & nonmetalsOkay conductors of heat & electricityShiny or dull
30 Who am I? Use the clues and a periodic table to predict the element. The number of clues is shown in the lower right corner.
31 1. Who am I? Very good ability to conduct electricity Never found alone in natureWhen combined with other elements, usually give up 1 valence electronOnly one letter in symbol4 clues
32 2. Who am I? More valence electrons than oxygen More protons than calciumFewer protons than krypton3 clues
33 3. Who am I? Poor conductor Usually found as a gas Do not bond well with othersSometimes found in signs outside restaurants4 clues
34 4. Who am I? Second lowest electronegativity of period One of most reactive in familyNot radioactiveAdd 50 protons and I’m now another element in my family4 clues
35 5. Who am I? Usually found as a gas Very reactive Lightest element in familyOften form -1 ion4 clues
36 6. Who am I? Radioactive Highest atomic radius in family Usually form -2 ion3 clues
37 7. Who am I? Never found alone or unbonded in nature Most commonly form +2 ionSecond highest number of protons in family3 clues
38 8. Who am I? All other members of family are metals Most abundant element in universe2 clues
39 9. Who am I? Metals, nonmetals, and semi-metals all found in family Same number of protons as the sum of the protons in the two elements directly above2 clues
40 10. Who am I? Highest ionization energy in family Family contains metals, nonmetals, and semi-metalsCan form positive or negative ion3 clues
41 Once you have finished, check your answers with a peer. That’s All Folks!Once you have finished, check your answers with a peer.