3 Periodic Periodic Law Periodic Table Something periodic occurs at regular or at least generally predictable intervalsPeriodic law - physical and chemical properties of the elements are periodic functions of their atomic numbersPeriodic Table of Elements – a table of the elements, arranged by atomic number, that shows the patterns in their properties; based on the periodic law
4 ElementA pure substance made up of one kind of atom that cannot be broken down into simpler substances by physical or chemical means90 occur naturally on earth25 were synthesized (made) by scientists
5 Dmitri MendeleevIn the 1860’s he devised a periodic table where the elements were ordered by their atomic massesHe did this by grouping elements together according to their similaritiesImage taken from:
6 Mendeleev’s Predictions Although Mendeleev’s Periodic Table of Elements had missing elements or “gaps”, he was able to predict the characteristics of these missing elements because of Periodic Law.
7 Henry MoseleyIn 1914, his work led to a revision of the periodic table by rearranging the elements by their atomic numbersHe concluded that the number of protons in an atom is its atomic numberImage taken from:
8 Classes of ElementsThis zig-zag staircase line separates the metals from the nonmetals. The elements along this line are sometimes called metalloids
9 What metal is not a solid MetalsLocationFound on the left of the zigzag line/staircase on the periodic table (exception Hydrogen)Chemical PropertiesHave few electrons in their outer energy level, thus lose electrons easilyPhysical Propertiesductile, good conductors, malleable, shiny, most are room temp.79Au11Na22.990Image taken from:What metal is not a solid@ room temperature?
10 Atoms with Few Electrons in their Outer Energy Level Notice: only 1 electron in outer level11Na22.990Sodium4Be9.012BerylliumNotice: only 2 electrons in outer level
11 Non-MetalsLocationMost found to the right of the zigzag line/staircase on the periodic tableChemical PropertiesMost have almost full outer energy levels, thus they tend to gain electrons; some have completely full outer levelPhysical Propertiesnot ductile or malleable, not shiny, poor conductors, most are solid, but some are gas at room temperature17Cl35.453Image taken from:16S32.066Image taken from:https://www.dmr.nd.gov/ndgs/rockandmineral/sulfur.asp
12 Atoms with Full or Almost Full Outer Energy Level 8O15.999OxygenNotice: 2 electrons in outer level – FULL2He4.003HeliumNotice: 6 electrons in outer level – almost fullNotice: 7 electrons in outer level – almost full9F18.998Fluorine
13 MetalloidsLocationBorder the zigzag line/staircase on the periodic tableChemical PropertiesMost atoms have ½ (≈) complete set of electrons in outer levelPhysical Propertieshave properties of both metals and non-metals14Si28.086Image taken from:5B10.811Image taken from:
14 Atoms with ½ (≈) Complete Outer Energy Level Notice: only 4 electrons in outer level5B10.811BoronNotice: only 3 electrons in outer level14Si28.086Silicon
15 Using the Periodic Table Atomic Number(Number of protons)Electron Configuration(Written in order of orbitals from top to bottom: top is innermost and bottom is outermost [valence])Element Symbol(Written with a capital letter or a capital followed by a lower case if two letters )Element NameAtomic Mass(Rounded to a whole number, equalsthe number of protons and neutrons)
16 Using the Periodic Table Letters are color coded based on the natural physical state of the elementThe boxes of each element are color coded based on the group (or subgroup) to which the element belongs
17 Today – 11/10/14 Complete Ch. 6 Vocabulary Page 197 (20 words) Due by end of class – NO EXCUSESBegin color-coding Periodic Table1 side:metals, nonmetals & metalloidsNames of groups2nd side: periodic trendsAtomic radiusIonic radiusIonization energyElectronegativity