6A little more history...Henry Moseley: Modern Periodic Table ( )There were small problems with Mendeleev’s table.Used information he found about isotopes to modify Mendeleev’s tableDetermined that elements are put in order by their atomic number
7Elements are arranged: Vertically into Groups/FamiliesHorizontally Into Periods
9If you looked at one atom of every element in a group you would see… Each atom has the same number of valence electrons Electrons in the outermost energy level (shell)
10The group 2 atoms all have 2 electrons in their outer shells Be (Beryllium)AtomMg (Magnesium) Atom
11The number of outer or valence electrons in an atom effects the way an atom bonds. The way an atom bonds determines many properties of the element.This is why elements within a group usually have similar properties.
12If you looked at an atom from each element in a period you would see… Each atom has the same number of energy levels.
13The period 4 atoms each have 4 energy levels 4th ShellKr (Krypton)AtomFe (Iron) AtomK (Potassium) Atom
14Divisions of the TableThe Periodic Table is divided into regions based on general propertiesInclude:MetalsNon-metalsMetalloids
16Metals Left side of the stairs Forms cations by losing electrons High Melting PointsSolids at room temperature (except Hg)Metallic lusterMalleable and ductileGood conductors of heat and electricity
17Non-metals Right side of the stairs Forms anions by gaining electrons Low Melting PointsGases or solids at room temperature (except Br2)Brittle solids (Which means what?)Insulators (poor conductors or heat & electricity)
18Metalloids Have properties of both metals and non-metals Semi-conductorsSolids
19Ticket Out The Door:State whether the following are metals, nonmetals, or metalloids and then predict a property that they may have:PotassiumIodineAntimony
30Halogens Group 17 Have 7 Valence electrons Most are poisonous Cl2 was used as a chemical weapon during WWI and WWII
31HalogensWhat trend in reactivity is seen amongst the Halogens?
32Noble Gases Group 18 8 Valence Electrons Very unreactive Gases at room temperature
33Jellyfish lamps made with noble gases artist- Eric Ehlenberger
34Lanthanides & Actinides Located at the bottom of the Periodic TableRare Earth MetalsLanthanide SeriesActinide Series
35Summing it up: Ticket out the Door State which group each of the following elements belongs to and give a property of the element.LithiumChlorineUraniumKryptonStrontiumChromium
36Bellwork What is the most reactive metal? What is the most reactive nonmetal?How many energy levels does Strontium have?How many valence electrons does Aluminum have?
37Blank Periodic TableWrite the names of the families in their respective columnsAlkali Metals, Alkaline Earth Metals, Halogens, & Noble GasesLabel the two rows with their respective namesLanthanides & ActinidesOutline the metals in REDOutline the metalloids in GREENOutline the non-metals in BLUEDraw an arrow showing reactivity of METALSDraw an arrow showing reactivity of NONMETALS
38PeriodicityThe properties of the elements on the periodic table create trends as you move around.Trends move left-right & up-down
39Reactivity of Metals Towards Francium Inc. down a column Inc. right to left across a periodWhy?Increase in Size (value of n)Larger in sizeIncrease Shielding effectWeaker nuclear chargeDecrease ionization energyTowards FranciumFr
40Reactivity of Nonmetals Inc. up a columnInc. left to right across a periodWhy?Decrease in size (value of n)Smaller in sizeDecrease Shielding effectStronger nuclear chargeIncrease ionization energyFTowards Fluorine
41Atomic Radius ½ the distance between two adjacent nuclei …increases as we go down a columnWHY?add a new energy level each time…increases as we go right to left across a periodDecrease in nuclear charge
42Atomic Radii = 1 Angstrom IA IIA IIIA IVA VA VIA VIIA Li Na K Rb Cs Cl PSiAlBrSeAsGeGaITeSbSnInTlPbBiMgCaSrBaBeFONCBIA IIA IIIA IVA VA VIA VIIA= 1 Angstrom
43Ionic Radius the size of an ion cations anions Ca atom Ca+2 ion Cl atomCl-1 ion20 p+20 p+17 p+17 p+20 e–18 e–17 e–18 e–Cl1–CaClCa2+cations lose electrons-smallerAnions gain electronslarger
44Atomic Radii Ionic Radii IA IIA IIIA IVA VA VIA VIIALiNaKRbCsClSPSiAlBrSeAsGeGaITeSbSnInTlPbBiMgCaSrBaBeBCNOFAtomicRadii0.95Li1+Be2+Na1+Mg2+Cl1-N3-O2-F1-S2-Se2-Br1-Te2-I1-Al3+Ga3+In3+Tl3+Ca2+K1+Sr2+Rb1+Cs1+Ba2+IonicRadiiCations: smallerthan parent atomsAnions: LARGERthan parent atoms= 1 Angstrom
45Ionization Energy Ionization Energy increases the energy required to remove an e– from an atom…increases as we go up a columnWHY?shielding effect - increase in the number of energy levels…increases as we go from left to right across a periodNonmetals tend to gain electrons… high 1st ionization energy.Metals tend to lose electrons… low first ionization energyHeIonization Energy increases
46Electronegativity electronegativity increases the tendency for a bonded atom to attract electrons to itself…increases as we go up a column…increases as we go left to right across a periodWHY?Nonmetals tend to gain electrons… high electronegativityMetals tend to lose electrons… low electronegativityFelectronegativity increases
47Periodic TableOn the periodic table on the next page of your notes… draw out all of the trends if you have not done so already.