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Chapter 5: The Periodic Table 5.1 Organizing the elements 5.2 The Modern Periodic Table 5.3 Representative groups.

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Presentation on theme: "Chapter 5: The Periodic Table 5.1 Organizing the elements 5.2 The Modern Periodic Table 5.3 Representative groups."— Presentation transcript:

1 Chapter 5: The Periodic Table 5.1 Organizing the elements 5.2 The Modern Periodic Table 5.3 Representative groups

2 Section 5.1 Organization of the Elements

3 Search for Order 1750 only 17 elements known 1789 Antoine Lavoisier grouped known elements (4 groups) Metals Non-metals Gases Earths Next 80 yrs scientists looked for better way to classify known elements

4 Mendeleev’s Periodic Table 1869….Dmitri Mendeleev (Russian teacher and chemist) organized known elements while playing solitaire Made deck of cards with elements Listed name, mass and properties Paid attention to how elements reacted in chemical reactions

5 Mendeleev’s Periodic Table Strategy for organization: What did he look at? chemical properties physical properties atomic mass density color melting point Valence electrons (sec 5.3)

6 Mendeleev’s Proposal Elements arranged in rows based on increasing mass. Elements with similar properties are in same column. Chart was a Periodic Table - arrangement of elements in columns based on a set of properties that repeat.

7 Mendeleev’s Prediction Table incomplete– elements not yet discovered Left spaces in table for undiscovered elements Good models allow for predictions to be made based on model Used properties of nearby elements to predict properties of unknown elements

8 He called this element eka-Aluminum. Later it was renamed Gallium after its discovery in 1875

9 Evidence Supporting Mendeleev’s Table Close match between Mendeleev’s predictions and the actual properties of new elements showed how useful table was. Ex. Discovery of: Aluminum, Gallium, Scandium, and Germanium ble.mov

10 Section 5.2 The Modern Periodic Table The Elements by Tom Lehrer YOU NEED 3 DIFFERENT COLORED PENCILS

11 The Modern Periodic Table “Periodic” - Repeating patterns Listed in order of increasing number of protons (atomic #) Properties of elements repeat Periodic Law- Periodic Law- when elements arranged by increasing number of protons, properties repeat in pattern

12 Columns in the Periodic Table -vertical (up & down) -called groups or families -#ed 1-18 or 1A through 8A -elements in same family have similar properties

13 Rows in the Periodic Table -horizontal (left – right) -called a period -properties change greatly across period -first element in period is very active metal -last element in most periods is noble gas -7 periods (number them on your periodic table)

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15 Element Key Important information about an element is given in each square of the periodic table: its atomic number chemical symbol element name average atomic mass 6 C Carbon For example: Carbon has atomic # 6 (or has 6 protons), an average atomic mass of and a symbol of C

16 Atomic Mass Two isotopes of copper 72% copper-63 28% copper-65 Makes the average amu

17 Determining Average Atomic Mass

18 Metals Most solids (Hg is liquid) Luster – shiny. Ductile – drawn into thin wires. Malleable – hammered into sheets. Conductors of heat and electricity. Include transition metals – “bridge” between elements on left & right of table

19 Non-Metals Properties are generally opposite of metals Poor conductors of heat and electricity Low boiling points Many are gases at room temperature Solid, non-metals are brittle (break easily) Chemical properties vary

20 Metalloids stair-step pattern Have properties similar to metals and non-metals Ability to conduct heat and electricity varies with temp Better than non-metals but not metals

21 Variation Across a Period: Left to Right Physical and Chemical properties Atomic size decreases Metallic properties decrease Ability to lose an electron decreases Ability to gain electrons increases

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23 Section 5.3 Representative Groups The Elements Hip Hop Classroom

24 What are Valence electrons? outermost e-’s Responsible for chem props Elements in same group… same # of VE ALL atoms want full outer energy level (usually 8 VE) To get full outer energy level, some elements: lose e- (metals) gain e- (non-metals) share electrons (some non-metals & metalloids)

25 Introducing the ten major groups (families) on the modern Periodic Table:

26 Alkali Metals - 1 valence electron (VE) - soft, silver-white, shiny metals - never found pure - most reactive metals - Reactivity increases down group reactivity increases potassium

27 Label the Alkali Metals to your PT

28 Alkaline Earth Metals - 2 VE - not as reactive as alkali metals - often mixed with Al - forms strong/light weight alloys magnesium

29 Alkaline Earth Metals Magnesium Used to make steel (light metal w/o losing strength) photosynthesis (chlorophyll) Calcium bones & teeth Chalk, limestone, pearls, plaster

30 Label the Alkaline Earth Metals to your PT

31 Boron Family Boron Hard/brittle never found pure in nature in borax...used to make detergents & cosmetics -3 VE

32 Boron Family Aluminum most abundant metal in earth’s crust important metal for industry light, strong, slow to corrode 13 Al Aluminum Aluminum

33 Label the Boron Family on your PT

34 Carbon Family - 4 VE - Can gain 4 e-, lose 4 e-, or share e- - Most compounds in body contain C - Si 2 nd most abundant element in Earth’s crust - Si used to tip saw blades silicon

35 Label the Carbon Family on your PT

36 Nitrogen Family - 5 VE - Tend to gain 3 e- - N and P used in fertilizers - P on tips of matches Arsenic

37 Label the Nitrogen Family on your PT

38 Oxygen Family - 6 VE - Tend to gain 2 e- - O very abundant element - S used in fertilizers - O needed for digestion sulfur

39 Label the Oxygen Family on your PT

40 Halogen Family (“salt-former”) -7 VE -most active nonmetals -never found pure in nature -react with alkali metals easily (forms salts) -F most active halogen

41 Halogens cont… F compounds in toothpaste Cl kills bacteria I keeps thyroid gland working properly bromine

42 Label the Halogen Group on your Periodic Table

43 The Noble Gases (Inert Gases) - non-reactive - outermost e- shell is full (8 VE) - In “neon” lights -in earth’s atmosphere (less than 1%) Neon

44 Label the Noble Gases on your Periodic Table

45 Transition Metals Almost all solids at room temp (Hg exception) ductile, malleable, conductors VE varies Less Reactive than Groups 1 & 2 Fe, Co, and Ni produce magnetic field mercury

46 Label the Transition Metals on your periodic table

47 Rare Earth Elements Lanthanide series (period 6) Actinide Series (period 7) Some radioactive Separated from table to make easy to read/print silver, silvery-white, or gray metals. Conduct electricity uranium

48 Label the Lanthanide Series on your PT

49 Label the Actinide Series on your PT

50 You may watch more videos about the elements at: or sing along at: hip hop classroom elemental funkiness - Mark Rosengarten


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