1 Unit 4: Periodic Table & Periodic Trends EQ: How does the organization of the periodic table allow us to make predictions or determine the behavior & properties of elements?
2 GPSSC4. Students will use the organization of the Periodic Table to predict properties of elements.a. Use the Periodic Table to predict periodic trends including atomic radii, ionic radii,ionization energy, and electronegativity of various elements.b. Compare and contrast trends in the chemical and physical properties of elements andtheir placement on the Periodic Table.
3 Key Vocabulary Terms Law of Octaves Periodic Table Periodic Law PeriodsGroup/ FamilyValence ElectronPeriodic TrendsAtomic RadiusIonic RadiusIonization EnergyElectronegativityElectron Affinity
4 The History Dobereiner Found elements could be put in Triads Newlands Discovered the Octet Rule when classifying elementsMendeleevFirst to organize elements by increasing mass to create the Periodic Table
5 J. W. Dobereiner ( )Observed that several elements could be classified into sets of three a.k.a. TriadsHis Triads included….Lithium, Sodium, and PotassiumCalcium, Strontium, and BariumChlorine, Bromine, and Iodine
6 Triads Grouped By Similar Chemical Properties Many Properties of Middle Elements Are Approximate Averages Of The Properties Of The 1st And 3rd Element
7 EXAMPLE ELEMENT ATOMIC MASS Density Cl 39.5 1.56 Br 79.9 3.12 L 126.9 4.95
8 J.A.R. Newlands ( )Presented the idea that when the elements were arranged in order of increasing atomic mass, the properties of every eighth element was like that of the first in the set:1st-8th, 2nd-9th, and so onCalled the pattern the law of octaves
9 Dmitri Mendeleev (1834-1907) Lothar Myer (1830-1895) Published nearly identical schemes for classifying the elementsMendeleev is given more credit since he published first and was more successful at demonstrating itMendeleev also put breaks in the Table where other elements were yet to be found b/c he knew they had to fit in to make the table work right
10 MendeleevNoticed that when he arranged the elements by increasing atomic mass he could see a periodic repetition of their propertiesUsed this to create the first Periodic TableWanted to make the elements easier to learn and understand
11 Moseley Moseley Developed atomic number concept for the atom Arranged elements by increasing atomic number rather than mass as Mendeleev had
12 The Periodic Lawwhen elements are arranged in order of increasing atomic number, their physical and chemical properties show a periodic pattern
13 A. Periodic LawWhen elements are arranged in order of increasing atomic #, elements with similar properties appear at regular intervals.
14 Reading the TableGroups/Families are elements with similar properties and run up and down. There are 18 families.Periods run left to right on the table. There are 7 periods.Groups to remember(1)- Alkali Metals(2)- Alkaline-earth Metals(3-12)- Transition Metals; d-blockInner transition Metals (bottom); f-block(17)-Halogens(18)- Nobel Gases
15 Reading the Table (Cont.) MetalsHave luster (a shine)Good conductors (of heat & electricity)Solids usuallyMalleable (can be pounded into sheets)Ductile (pulled into a wire)NonmetalsNo lusterPoor conductorsMany are GasesBig variation in physical propertiesMetalloids/ semi-metals--Have properties of metals and nonmetals-form the steps; except Al.
16 Electrons and The Table Electrons fill atoms in s-, p-, d- and f- orbitals. These orbitals have a location on the P.T.S-block: left side.P-block: right side.D-block: Transition Metals.F-block: Inner Transition Metals.
17 Classification of the Elements The periodic table is divided into blocks that correspond to the sub-levels that are being filled with electronsS block: Group 1& 2P block: Groups (except for Helium)D block: transition metalsF block: inner transition metals
18 Classification of the Elements The periodic table is one of the most important tools in chemistryElements are arranged according to atomic number, but the periodic table also relates to atomic structure and trends among the elementsElements can be classified into 4 categories according to their electron configurations
19 Classification of the Elements The noble gasesElements in which the outermost s and p sublevels are filledAlso known as inert gasesThe representative elementsElements in which the outermost s or p sublevel is only partially filledUsually called the Group A elementsGroup 1 elements are the alkali metalsGroup 2 elements are the alkaline earth metals
20 Important Group names Alkali Metals Alkaline Earth Metals Transition MetalsHalogensNoble Gases
21 Classification of the Elements The transition metalsMetallic elements in which the outermost s sublevel and nearby d sublevel contain electronsCalled the Group B elementsCharacterized by the addition of electrons to the d orbitalsThe inner transition metalsMetallic elements in which the outermost s sublevel and the nearby f sublevel generally contain electronsCharacterized by the filling of f orbitals