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The Periodic Table of Elements. What is the Periodic Table?. It is an organizational system for elements. Picture from www.chem4kids.com. Why is the Periodic Table Important?. The periodic table is the most useful tool to a chemist.
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What is the Periodic Table? • It is an organizational system for elements. Picture from www.chem4kids.com
Why is the Periodic Table Important? • The periodic table is the most useful tool to a chemist. • It organizes lots of information about all the known elements http://www.youtube.com/watch?v=lDp9hUf_SV8&edufilter=vH8ntV7keCE-ZLl5wRMzNg
Remember that an Element • Is a pure substance made up of one kind of atom that cannot be broken down into simpler substances by physical or chemical means • 90 occur naturally on earth • 25 were synthesized (made) by scientists Element Song http://www.privatehand.com/flash/elements.html http://www.scienceraps.co.uk/rap_science_periodic_table.html
Who created the it?Dmitri Mendeleev In 1869, Russian chemist Dimitri Mendeleev proposed arranging elements by atomic weights and properties. 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
Who was Henry Moseley? • Arranged elements by atomic number instead of mass • Realized that there were undiscovered elements Image taken from: http://dewey.library.upenn.edu/sceti/smith/
So how is it arranged? • The genius of the periodic table “is that it is organized like a big grid. The elements are placed in specific places because of the way they look and act. If you have ever looked at a grid, you know that there are rows (left to right) and columns (up and down). The periodic table has rows and columns, too, and they each mean something different.” • quoted fromhttp://www.chem4kids.com/files/elem_pertable.html
Periods =Rows • Even though they skip some squares in between, all of the rows go left to right. When you look at a periodic table, each of the rows is considered to be a different period (Get it? Like PERIODic table.) • quoted fromhttp://www.chem4kids.com/files/elem_pertable.html
Groups=Columns • The periodic table has a special name for its columns, too. When a column goes from top to bottom, it's called a group. • quoted fromhttp://www.chem4kids.com/files/elem_pertable.html
Metals Location • Found on the left of the zigzag line/staircase on the periodic table Chemical Properties • Reactivity- ease and speed with which an element combines with other elements or compounds • Have few electrons in their outer energy level, thus lose electrons easily Physical Properties • ductile, good conductors of heat and electricity, malleable, shiny, most are solid @ room temperature Image taken from: http://chemistry.about.com/od/periodictableelements/ig/Element-Photo-Gallery.--98/Sodium.htm What metal is not a solid @ room temperature?
- + + - - + + + + + - - - - + - - + + + + + - - + + - - - - Atoms with Few Electrons in their Outer Energy Level Notice: only 1 electron in outer level Notice: only 2 electrons in outer level
Non-Metals Location • Most found to the right of the zigzag line/staircase on the periodic table Chemical Properties • Most have almost full outer energy levels, thus they tend to gain electrons; some have completely full outer level Physical Properties • not ductile or malleable, Dull, Brittle , poor conductors, most are solid, but some are gas at room temperature Image taken from: http://nobel.scas.bcit.ca/resource/ptable/cl.htm Image taken from: https://www.dmr.nd.gov/ndgs/rockandmineral/sulfur.asp
- + + + + - - - - - - + + + + - - + + + + + + + - + + - - + + - - - - - - - Atoms with Full or Almost Full Outer Energy Level Notice: 2 electrons in outer level – FULL Notice: 6 electrons in outer level – almost full Notice: 7 electrons in outer level – almost full
Metalloids Location • Border the zigzag line/staircase on the periodic table Chemical Properties • Outer electron shells are about half-full Physical Properties • have properties of both metals and non-metals Image taken from: http://library.thinkquest.org/C0113863/bios.shtml Image taken from: http://library.thinkquest.org/C0113863/bios.shtml
- - - + - - - - + + + + + + + - + + + + + - + - - - - + + + + + - - - - - - Atoms with ½ (≈) Complete Outer Energy Level Notice: only 4 electrons in outer level Notice: only 3 electrons in outer level
Coloring Periodic Table(Homework) • Title “The Periodic Table of Elements” • Create Element Key • Draw Zigzag • Number periods and groups • Color Metals ORANGE • Color Nonmetals BLUE • Color Metalloids GREEN
The periodic table is divided into horizontal rows called PERIODS Periods are numbered 1-7 How many periods (rows) are on the Periodic Table Of Elements? FROM LEFT TO RIGHT OR RIGHT TO LEFT
Period (Row) Properties • Seven periods on a periodic table (numbered from the top down) • Atomic numbers and atomic masses increase as you move from the left to the right in a period • All atoms of the elements in the same period have the same number of orbitals/levels • Example • Period 1 = 1 orbital • Period 2 = 2 orbitals • Period 3 = 3 orbitals • 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?
The Periodic Table is divided into vertical columns: Group (Family) • each column of elements on the periodic table 1-18 How many groups (families) are on the Periodic Table Of Elements? FROM TOP TO BOTTOM OR BOTTOM TO THE TOP
Group (Family) Properties • 18 groups (numbered from left to right) • Atoms of elements in the same group have the same number of valence electrons Exceptions: • Transition elements (3-12) • Helium (actually has 2 valence electrons) • Elements in groups usually have similar physical and chemical properties • Families have names rather than numbers (just like your family)
1 H 1.008 3 Li 6.941 + 11 Na 22.990 + + - 19 K 39.098 - - + 37 Rb 85.468 - - + + + + 55 Cs 132.905 + - - + + 87 Fr (223) - - - - Examples of Group 1 Elements with the same # of valence electrons How many electrons do each of these atoms have in their outer orbital/level? What group (family) do these elements reside in?
Group (Family) Names Alkali Metals Alkaline Earth Metals Noble Gases Boron Group Nitrogen Group Carbon Group Oxygen Group Halogens Transition Metals
Identify the Element Period 2 – Group 14 Period 5 – Group 2 Group 17 – Period 6 Group 4 – Period 7 Rutherfordium - Rf Carbon - C Strontium - Sr 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) 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) What is Oxygen’s physical state of matter? Which class does Oxygen fall into?
Hydrogen • Hydrogen belongs to a family of its own. • Rarely found as pure element, mostly in H20 • Hydrogen is a diatomic, reactive gas. • Hydrogen was involved in the explosion of the Hindenberg.
Alkali Metals • Group 1 Elements: (not including Hydrogen) Lithium, Rubidium Sodium, Cesium Potassium, Francium MOST reactive metals, never found uncombined in nature (like in salt). • 1 electron in the outer shell • Soft and silvery metals • Conduct electricity
Alkaline Earth Metals The Group 2 Elements Beryllium, Magnesium, Calcium Strontium, Barium ,Radium • 2 electrons in the outer shell • White and malleable • Reactive, but less than Alkali metals • Conduct electricity • Several of these elements are important mineral nutrients (such as Mg and Ca)
Transition Metals • Elements in groups 3-12 • Less reactive, harder metals • Good conductors of heat and electricity. • Some are used for jewelry. • The transition metals are able to put up to 32 electrons in their second to last shell. • Can bond with many elements in a variety of shapes.
Boron Family • Elements in group 13 Boron ,Aluminum, Gallium, Indium, Thallium • Aluminum metal was once rare and expensive, not a “disposable metal.” • Elements have 3 valence electrons. • All are metals except Boron (metalloid) • Aluminum is the most common metal in the Earth’s crust.
Carbon Family • Elements in group 14 Carbon, Silicon, Germanium, Tin, Lead • Contains elements important to life and computers. • Carbon is the basis for an entire branch of chemistry. • Elements have 4 valence electrons • Silicon is used to make semiconductors for computers and other electronics . • Diamond and Graphite are two forms of carbon.
Nitrogen Group • Elements in group 15 • Nitrogen makes up over ¾ of the atmosphere. • Nitrogen and phosphorus are both important in living things. • The red stuff on the tip of matches is phosphorus. • Elements have 5 valence electrons • Can share electrons to form compounds • Contains metals, metalloids, and non-metals
Oxygen or Chalcogens Family • Elements in group 16 Oxygen, Sulfur, Selenium, Tellurium, Polonium • Oxygen is necessary for respiration. • Many things that stink, contain sulfur (rotten eggs, garlic, skunks, etc • About 20% of the Earth’s atmosphere is oxygen.
Halogens • Elements in group 17 • Fluorine, chlorine, bromine and iodine • Very reactive, volatile, diatomic, nonmetals • Always found combined with other elements in nature. • Used as disinfectants and to strengthen teeth. • The Halogens form salts with the alkali metals. • Fluorine is an active ingredient in toothpaste
The Noble Gases • Elements in group 18 Helium, Neon, Argon, Krypton, Xenon, Radon • VERY unreactive, monatomic gases • Used in lighted “neon” signs • Do NOT ordinarily form compounds. • Have a full valence shell
The Lanthanides and The Actinides • The Lanthanides • Soft metals that can be cut with a knife. • Were once called rare earth metals. • Glass used in computer and TV screens contain Yttirum and Europium • The Actinides • All actinides are radioactive. • Thorium, Proactinium and Uranium are the only actinides found naturally on earth. • Plutonium is used to fuel nuclear powerplants.
What is an ION? • Charged atoms (or groups of atoms) are called ions. • An atom becomes charged by either gaining or losing one or more electrons. • An atom that has lost one or more e- is a positive ion or (cation). The atom now has more protons than e-. • An atom that has gained one or more e- is a negative ion (anion). The atom now has more e- than protons.
The Periodic Table Song • http://www.youtube.com/watch?v=zUDDiWtFtEM&edufilter=vH8ntV7keCE-ZLl5wRMzNg