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Introduction to the Periodic Table - A Comprehensive Overview

Learn about Dmitri Mendeleev's organization of elements, the properties of rows and columns, valence electrons, and the categorization of elements into metals, nonmetals, and metalloids.

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Introduction to the Periodic Table - A Comprehensive Overview

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  1. Do Now • Sit SILENTLY and pull out your notebooks • Copy these questions and prepare to answer them while watching the video after role is called. • What was Newland’s initial theory/law called? • Who eventually streamlined the periodic table? • What was the element that proved the periodic table worked? Why?

  2. Periodic Table http://app.discoveryeducation.com/techbook2:concept/view/guidConceptId/28cfb3b0-09e8-44ac-8fe7-0d04a065e60e/guidUnitId/e88cf548-8791-48c3-9cd8-8cac59c61950#/tab=model-lesson-tab&page=1&subTab=session2

  3. DmitriMendeleevorganized the known elements into a table called the periodic table. He organized them by their increasing atomic masses.

  4. Today we organize theelementsby their increasingAtomicNumber.

  5. Insert copy of the periodic table.

  6. Rows on the periodic table are called periods. All the elements listed in a row belong to the same period. There are 7 (seven) periods.

  7. Columns in the periodic table are called groups or families. All elements in a group have similar properties.

  8. Insert copy of the periodic table. The columns have been given an Arabic number. The columns are numbered 1 – 18 starting at the left and moving to the right.

  9. Valence Electrons The outer most energy level is usually not full or complete . These electrons in the outer energy level are called Valenceelectrons. Valence electrons are important because they determine how an element willreactwith other substance.

  10. Insert picture of periodic table. In group 1 and 2 the number of Valence electrons in the outer energy level willmatchthe group number.

  11. Insert picture of periodic table. Groups 3 through 12 do not follow any particular rule to determine the number of Valence electrons.

  12. Insert picture of periodic table. In groups 13 to 18 – The Valence electrons for each of these is the group number minus10.For example Group 14 –10= 4 Valence electrons.

  13. Elements whose atoms gain, lose (ionic bonding)orshare (covalent bonding)electrons are reactive, and they combine to form the many compounds we use in our daily lives.

  14. Elements are categorized as metals, nonmetals or metalloids. Metal: Anelementthat has luster, ismalleableandductile, and is said to be a good conductor of heat andelectricity.

  15. What is luster, malleable and ductile? Luster describes the way a surface reflects light…therefore metallic luster would be shiny like a metal object. Malleable means to be able to press or pound the substance into sheets or different shapes. Ductile means that the substance can be drawn out into thin wires.

  16. Elements are categorized as metals, nonmetals or metalloids (cont’). Nonmetals: Elements that are usually agasor abrittlesolid at room temperature. It is a poor conductor of heat andelectricity.

  17. Elements are categorized as metals, nonmetals or metalloids (cont’). Metalloid: an element thatsharessome characteristics or properties with bothmetalsand nonmetals.

  18. Group 1 and 2 Elements: These elements are so reactive that they are only found combined with other elements in nature.

  19. Group 1: Alkali Metals • Soft – can be cut with a knife • Shiny andsilver colored • LowDensity (some will even float) • Mostreactiveof the metals • Valence electrons = 1 • Reactsviolentlywith water forming a hydrogen gas • Compounds from these are very useful such as NaCl • http://app.discoveryeducation.com/techbook2:concept/view/guidConceptId/28cfb3b0-09e8-44ac-8fe7-0d04a065e60e/guidUnitId/e88cf548-8791-48c3-9cd8-8cac59c61950#/tab=model-lesson-tab&page=1&subTab=sessions3and4

  20. Group 2:Alkaline- Earth Metals • Very reactivebut not as reactive as Alkali Metals. • Silver colored • Moredensethan Group 1 metals • Valence electrons =2 • Useful compounds include: Calcium compounds such as cement, plaster, chalk, and YOU. • http://app.discoveryeducation.com/techbook2:concept/view/guidConceptId/28cfb3b0-09e8-44ac-8fe7-0d04a065e60e/guidUnitId/e88cf548-8791-48c3-9cd8-8cac59c61950#/tab=model-lesson-tab&page=1&subTab=sessions3and4

  21. Group 3 to 12:TransitionMetals

  22. Group 3 to 12:TransitionMetals • Do not lose their valenceelectrons as easily as groups 1 & 2. • Less reactive thanAlkaliandAlkalineEarth metals • Shiny • Goodconductorsof electricity • Higherdensity and melting points (except mercury) than Group 1 and 2

  23. Group 3 to 12: Transition Metals (cont’.) • Lanthanides: The first row underneath the periodic table: Shiny, reactive, many are used in the production of steel. • Actinides: The second row underneath the periodic table: These elements are allradioactiveand unstable.. Note: Elements found after 94 (Plutonium) are man made and not found in nature

  24. Group 13:BoronGroup • Reactive • Valence electrons = 3 • Contains1Metalloid and4Metals • Solidat room temperature • Aluminumis the most abundant in this group and the most common in the Earth’s crust

  25. Group 14:Carbon Group • Reactivityvariesin this group depending on the element • Valence electrons =4 • This group contains2metals, 1nonmetal and2metalloids. • Many forms founduncombinedin nature such as diamonds • Compounds are very useful:proteins, fats, carbohydrates, computer chips.

  26. Group 15:Nitrogen Group • Reactivityvariesin this group depending on the element • Valence electrons =5 • Group contains1metal, 2Nonmetals, and2metalloids • Phosphorous is veryreactiveand only found in naturecombinedwith other elements. • All butnitrogenare solid at room temperature. • Nitrogen makes up78%of our atmosphere. • Generallyunreactive.

  27. Group 16: Oxygen Group • More reactivethan group 15 • Valence electrons =6 • Group contains1Metals, 3Nonmetals and1Metalloids • Sulfur is found in nature and is used to makesulfuricacid, a very commonly used chemical in industry. • All butoxygenare solid at room temperature. • Oxygen makes up21%of the Earth’s Atmosphere • Oxygen is very reactive and combines with many other elements especially metals • Rustis the result of the oxidation of metal.

  28. Group 17:Halogen Group • Veryreactive • Valence electrons = 7 • Nonmetal group • PoorConductors of electricity and heat • Reactviolently with alkali metals to form salts • Never founduncombinedin nature • Atoms of these elements only need to gain 1 electron to fill their outer shell • Chlorine andIodineare both in this group and can be combined to make disinfectants. • http://app.discoveryeducation.com/techbook2:concept/view/guidConceptId/28cfb3b0-09e8-44ac-8fe7-0d04a065e60e/guidUnitId/e88cf548-8791-48c3-9cd8-8cac59c61950#/tab=model-lesson-tab&page=1&subTab=sessions3and4

  29. Group 18:Noble Gas Group • Non-reactant • Valence electrons =8 • Outermostenergy shell is full • Colorless, odorlessgases at room temp. • Under normal conditions they do notreactwith other elements • All found on Earth in very small amounts • Argonis the most common in the group • Their non-reactivity makes them very useful forlightbulbs, helium for blimps andweatherballoons. • http://app.discoveryeducation.com/techbook2:concept/view/guidConceptId/28cfb3b0-09e8-44ac-8fe7-0d04a065e60e/guidUnitId/e88cf548-8791-48c3-9cd8-8cac59c61950#/tab=model-lesson-tab&page=1&subTab=sessions3and4

  30. Hydrogen Stands Alone: • Properties do not match the properties of any single group • Valence Electrons = 1 • Easily looses that one valence electron • Physical properties are like the nonmetal group • Most abundant element in the Universe • Its reactive nature makes it useful as a fuel for rockets.

  31. Insert picture of periodic table.

  32. Periodic Table Exit Ticket Elements are arranged on the PTE by increasing what? Who came up with this organization? What do the valence electrons have to do with bonding/reactivity of an atom? What is a key characteristic of the noble gasses that makes them different from the other elements? (being a gas, is not the answer, think about how many valence electrons they have)

  33. Elementals Homework You will be assigned an element and you will need to do research on this element. You will make a foldable, and on the front you will design the block of the periodic table that your element appears in so that it has the same information that can be found on the periodic table. On the 2 sides of the open foldable, you will design and describe a superhero or super villain. That superhero/super villain needs to have properties or powers that line up with the properties of the element you were assigned. Draw the hero/villain on the left side and write the description of their powers on the right. Do this on colorful paper or use lots of colors in the drawing and fold the paper hamburger style not hot dog. We will post this as a giant periodic table in the hallway so everyone can see

  34. Chemical Bonds & Reactions - + + -

  35. Chemical Bond • A force of attraction that holds two atoms together (electromagnetic force) • Has a significant effect on chemical and physical properties of compounds • involves the valence electrons Valence Electrons – the electrons in the outermost energy level of an atom This Lithium Atom has one valence electron

  36. Counting Valence Electrons Carbon 4 valence electrons Beryllium 2 valence electrons Oxygen 6 valence electrons

  37. Determining the Number of Valence Electrons by Using the Periodic Table *Atoms of elements in Groups 1 and 2 have the same number of valence electrons as their group number. *Atoms of elements in Group 3-12 do not have a general rule relating their valence electrons to their group number. However, they typically have between 1 or 2 valence electrons. *Atoms of elements in Groups 13-18 have 10 fewer valence electrons than their group number. (Exception - helium atoms have only 2 valence electrons, even though they are in group 18)

  38. How Many Valence Electrons? 1 Valence Electron • Hydrogen • Lead • Xenon • Sulfur • Rubidium 4 Valence Electrons 8 Valence Electrons 6 Valence Electrons 1 Valence Electron

  39. The Octet Rule • Atoms will combine to form compounds in order to reach eight electrons in their outer energy level. • Atoms with less than 4 electrons tend to lose electrons. • Atoms with more than 4 electrons tend to gain electrons. • Be aware that there are some exceptions! CONSIDER EIGHT A HAPPY NUMBER FOR ATOMS!

  40. + + + - - - + - - + + + + + - - + + - - - - The Octet Rule In Action 6 7 Notice how this chlorine atom has seven valence electrons, one away from eight. It will try to gain one more according to the Octet Rule. 5 4 1 1 2 3 Notice how the sodium atom has one valence electron. It is this electron that it will try to get rid of according to the Octet Rule. Where do you think Chlorine finds that one electron that it needs?

  41. Lewis Structure(Electron Dot Diagram) • a way of drawing the outer energy level electrons (valence) of an atom • The symbol for the element surrounded by as many dots as there are electrons in its outer energy level (valence) • Examples How many valence electrons do each of these atoms have?

  42. Making an Electron Dot Diagram Element “X” has 8 valence electrons Write down the element’s symbol and place the first two dots on any side of the symbol. 3 2 1 If this were an atom of an element from group 1, you would just place the one dot on any side of the element. Place the rest of the dots in either a clockwise or counter clockwise manner around the symbol, with no side receiving two dots until each side gets one. 7 6 4 5

  43. What Would the Electron Dot Diagram Look Like? 1 Valence Electron 6 Valence Electrons H O How many valence electrons does each atom have? Ne Sr 2 Valence Electrons 8 Valence Electrons

  44. Oxidation Number • The charge that an atom would have if it lost or gained electrons; ionic charge • Can be helpful in determining which atoms will interact or bond with each other • Example: According to electron dot diagram for Magnesium, it has two valence electrons. Because Magnesium is “unhappy” with two, it will typically lose them. If this happens it will turn into a Magnesium ion. At this point it will have an oxidation number of +2. 2+ Mg

  45. H O Ne Sr What Could the Oxidation Number Be? +1 or -1 because it can gain or lose one electron -2 because it will gain two electrons 0 because it will not gain or lose electrons +2 because it will lose two electrons

  46. 3 Types of Chemical Bonds • Ionic • Covalent • Metallic What can you describe about each of these bonds just by looking at the name?

  47. The force of attraction between oppositely charged ions. Occurs after a transfer or loss/gain of electrons Usually form between atoms of metals and atoms of non-metals Resulting compounds have a name that usually ends in –ide IONIC BONDS 1+ 1- Na Cl Which different groups or families of elements will most-likely interact to create these types of bonds? - Example - Sodium Chloride (NaCl)

  48. + + O + + + + H + + H COVALENT BOND • A force that bonds two atoms together by a sharing of electrons • Each pair of shared electrons creates a bond • Usually occurs between atoms of non-metals - - - - - + + - - - - - Example – Water (H2O)

  49. Types of Covalent Bonds • Different covalent bond types share a different number of electrons Water (H2O) Carbon Dioxide (CO2) Nitrogen (N2) Single Bonds Share 2 Electrons Double Bonds Share 4 Electrons Triple Bonds Share 6 Electrons

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