The Periodic Table of Elements

Periodic  Periodic Law  Periodic Table Something periodic occurs at regular or at least generally predictable intervals Periodic law - physical and chemical properties of the elements are periodic functions of their atomic numbers Periodic Table of Elements – a table of the elements, arranged by atomic number, that shows the patterns in their properties

Atoms, Elements, Molecules What is the difference between the 3? Atoms: The basic building blocks of matter that make up everyday objects. Ex) H2O – 3 atoms, CO2 – 3 atoms, C6H12O6 – 24 atoms Elements: Pure substances that cannot be broken down chemically. Ex) Carbon (C), Hydrogen (H), Oxygen (O) Molecules: Two or more atoms joined together chemically. Ex.) O2 – 1 molecule, 2H2O – 2 molecules

Dmitri Mendeleev Invented the PTE in the 1860’s and arranged elements by atomic mass. He did this by grouping elements together according to their similarities Draft of Mendeleev's Periodic Table Image taken from: http://jscms.jrn.columbia.edu/cns/2006-04-18/fido-luxuriantflowinghair/mendeleev/

Mendeleev’s Published Periodic Table of Elements Why do you think there are question marks here? Image taken from: http://www.chemsoc.org/networks/learnnet/periodictable/post16/develop/mendeleev.htm

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. “Ekasilicon” Germanium Notice how Mendeleev’s predictions (orange column) were very accurate when compared to Germanium’s actual characteristics (green column) Date Predicted 1871 Date Discovered 1886 Atomic Mass 72 72.6 Density 5.5 g/cm3 5.47 g/cm3 Bonding Power 4 Color Dark Gray Grayish White

Henry Moseley He revised the original PTE in to the modern day PTE by placing elements in order by atomic NUMBER. He concluded that the number of protons in an atom is its atomic number. Image taken from: http://dewey.library.upenn.edu/sceti/smith/

3 Classes of Elements Using this as a guide, color code your periodic table to show the three classes. Start by highlighting the “zig-zag.” Class Color Metal Non-Metal Metalloid

What metal is not a solid Metals Location Found to the LEFT of the zigzag line (except Hydrogen) Chemical Properties Have few electrons in their outer energy level Tend to LOSE valence electrons easily 79 Au 196.967 11 Na 22.990 Image taken from: http://chemistry.about.com/od/periodictableelements/ig/Element-Photo-Gallery.--98/Sodium.htm What metal is not a solid @ room temperature?

Metals Physical Properties: 1. Malleable: Can be bent or hammered flat 2. Ductile: Can be drawn into wire 3. Tensile strength: Are strong and resist bending and breaking 4. Have high melting and boiling points 5. Good conductors of heat and electricity 6. Have high densities (heavy weight for their size) 7. Attracted to a magnet 8. Shiny Luster

Atoms with Few Electrons in their Outer Energy Level 11 Na 22.990 Notice: only 1 electron in outer level + - + - 4 Be 9.012 Notice: only 2 electrons in outer level

Non-Metals Location Found to the RIGHT of the zigzag line Chemical Properties Most have almost full outer energy levels Tend to GAIN valence electrons 17 Cl 35.453 Image taken from: http://nobel.scas.bcit.ca/resource/ptable/cl.htm 16 S 32.066 Image taken from: https://www.dmr.nd.gov/ndgs/rockandmineral/sulfur.asp

Nonmetals Physical Properties: Good insulators Exist as solids, liquids and gases at room temperature Dull Luster Brittle Not malleable or ductile Low tensile strength (soft and bend/break easily) Low melting and boiling points Poor conductors of heat and electricity Low densities Not attracted to metal

Atoms with Full or Almost Full Outer Energy Level + - 8 O 15.999     + - Notice: 2 electrons in outer level – FULL 2 He 4.003 + - Notice: 6 electrons in outer level – almost full Notice: 7 electrons in outer level – almost full 9 F 18.998

Metalloids Location BORDERS the zigzag line Chemical Properties: Elements on the right of zigzag GAIN valence electrons. Elements on the left of zigzag LOSE valence electrons. 14 Si 28.086 Image taken from: http://library.thinkquest.org/C0113863/bios.shtml 5 B 10.811 Image taken from: http://library.thinkquest.org/C0113863/bios.shtml

Metalloids Physical Properties 1. Most are solids 2. May or may not be: malleable, ductile, or brittle 3. Conducts heat and electricity better than nonmetals, but not as well as metals. 4. Good semiconductors 5. Has densities and melting/boiling points that are widely varied. 6. Has shiny AND dull lusters

Important Features of the Periodic Table: Period (Row) each horizontal row of elements on the periodic table How many periods (rows) are on the Periodic Table Of Elements? FROM LEFT TO RIGHT OR RIGHT TO LEFT

Period (Row) Properties Seven periods (numbered from the top down) Atomic numbers & masses increase as you move from left to the right in a period. All atoms of the elements in the same period have the same number of rings. Example Period 1 = 1 ring Period 2 = 2 rings Period 3 = 3 rings Etc…

Examples of Period (Row) elements having the same number of orbitals/levels in their atoms + - + - In what period (row) do you think these atoms reside? + - + - In what period (row) do you think these atoms reside?

How many groups (families) Important Features of the Periodic Table: Group (Family) each column of elements on the periodic table How many groups (families) are on the Periodic Table Of Elements? FROM TOP TO BOTTOM OR BOTTOM TO THE TOP

Group (Family) Properties Eighteen families (numbered from left to right) Atomic numbers & masses increase as you move from the top down in a group (family) Atoms of elements in the same group have the same number of electrons in the outer rings (known as valence electrons) When bonding we refer to families as GROUPS. There are 8 Groups. (we skip transition metal families. Elements in groups have similar physical and chemical properties

Examples of Group Elements with the same # of valence electrons                            How many electrons do each of these atoms have in their outer orbital/level? 87 Fr (223) 55 Cs 132.905 37 Rb 85.468 19 K 39.098 11 Na 22.990 3 Li 6.941 1 H 1.008 + - What group (family) do these elements reside in?

Group (Family) Names Alkali Metals Alkaline Earth Metals Noble Gases Boron Group Carbon Group Nitrogen Group Oxygen Group Halogens Transition Metals

Identify the Element Period 5 – Group 2  Group 4 – Period 7  Rutherfordium - Rf Strontium - Sr Carbon - C Astatine - At

Using the Periodic Table The boxes that make up the periodic table contain a significant amount of information. To understand this information, it is necessary to refer to the periodic table’s key(s) 8 O Oxygen 15.999 Atomic Number (Number of protons) Element Symbol (Written with a capital letter or a capital followed by a lower case if two letters ) Element Name Atomic Mass (Rounded to a whole number, equals the number of protons and neutrons) Class Color Metal Non-Metal Metalloid State (@ Room Temp.) Symbol Color Solid Liquid Gas What is Oxygen’s physical state of matter? Which class does Oxygen fall into?