Slide 1 of 28 Organizing the Elements 6.1

© Copyright Pearson Prentice Hall Organizing the Elements > Slide 2 of 28 Searching For an Organizing Principle By the year 1700, only 13 elements had been identified. But as scientists started to use scientific methods to search for elements, the rate of discovery started to increase. 6.1

Slide 3 of 28 © Copyright Pearson Prentice Hall Organizing the Elements > Searching For an Organizing Principle Chemists used the properties of elements to sort them into groups. 6.1

Slide 4 of 28 © Copyright Pearson Prentice Hall Organizing the Elements > Searching For an Organizing Principle In 1839, J. W. Dobereiner grouped elements into triads. A triad is a set of three elements with similar properties. Chlorine, bromine, and iodine have very similar chemical properties. 6.1

© Copyright Pearson Prentice Hall Organizing the Elements > Slide 5 of 28 Mendeleev’s Periodic Table In 1869, Dmitri Mendeleev, a Russian chemist, published the first periodic table. He arranged the elements in order of increasing atomic mass. 6.1

Slide 6 of 28 © Copyright Pearson Prentice Hall Organizing the Elements > Mendeleev’s Periodic Table The periodic table was used to predict the properties of undiscovered elements. 6.1

Slide 7 of 28 © Copyright Pearson Prentice Hall Organizing the Elements > Mendeleev’s Periodic Table An Early Version of Mendeleev’s Periodic Table 6.1

Slide 8 of 28 © Copyright Pearson Prentice Hall Organizing the Elements > The Periodic Law In the modern periodic table, elements are arranged in order of increasing atomic number. 6.1

Slide 9 of 28 © Copyright Pearson Prentice Hall Organizing the Elements >

Slide 10 of 28 © Copyright Pearson Prentice Hall Organizing the Elements > The Periodic Law The periodic law: When elements are arranged in order of increasing atomic number, there is a periodic repetition of their physical and chemical properties. - as a result, elements in the same group will have similar properties 6.1

Slide 11 of 28 © Copyright Pearson Prentice Hall Organizing the Elements > Group – vertical column Period – horizontal row

© Copyright Pearson Prentice Hall Slide 12 of 28 Organizing the Elements > Metals, Nonmetals, and Metalloids Three classes of elements are metals, nonmetals, and metalloids. Across a period, the properties of elements become less metallic and more nonmetallic. 6.1

© Copyright Pearson Prentice Hall Slide 13 of 28 Organizing the Elements > Metals, Nonmetals, and Metalloids Metals, Metalloids, and Nonmetals in the Periodic Table 6.1

© Copyright Pearson Prentice Hall Slide 14 of 28 Organizing the Elements > Metals, Nonmetals, and Metalloids Metals, Metalloids, and Nonmetals in the Periodic Table 6.1

© Copyright Pearson Prentice Hall Slide 15 of 28 Organizing the Elements > Metals, Nonmetals, and Metalloids Metals, Metalloids, and Nonmetals in the Periodic Table 6.1

© Copyright Pearson Prentice Hall Slide 16 of 28 Organizing the Elements > Metals, Nonmetals, and Metalloids Metals, Metalloids, and Nonmetals in the Periodic Table 6.1

Slide 17 of 28 © Copyright Pearson Prentice Hall Organizing the Elements > Metals, Nonmetals, and Metalloids Metals Metals are good conductors of heat and electric current. 80% of elements are metals. Metals have a high luster, are ductile, and are malleable. 6.1

Slide 18 of 28 © Copyright Pearson Prentice Hall Organizing the Elements > Metals, Nonmetals, and Metalloids Uses of Iron, Copper, and Aluminum 6.1

Slide 19 of 28 © Copyright Pearson Prentice Hall Organizing the Elements > Metals, Nonmetals, and Metalloids Uses of Iron, Copper, and Aluminum 6.1

Slide 20 of 28 © Copyright Pearson Prentice Hall Organizing the Elements > Metals, Nonmetals, and Metalloids Uses of Iron, Copper, and Aluminum 6.1

Slide 21 of 28 © Copyright Pearson Prentice Hall Organizing the Elements > Metals, Nonmetals, and Metalloids Nonmetals In general, nonmetals are poor conductors of heat and electric current. Most nonmetals are gases at room temperature. A few nonmetals are solids, such as sulfur and phosphorus. One nonmetal, bromine, is a dark-red liquid. 6.1

Slide 22 of 28 © Copyright Pearson Prentice Hall Organizing the Elements > Metals, Nonmetals, and Metalloids Metalloids A metalloid generally has properties that are similar to those of metals and nonmetals. The behavior of a metalloid can be controlled by changing conditions. 6.1

Slide 23 of 28 © Copyright Pearson Prentice Hall Organizing the Elements > Metals, Nonmetals, and Metalloids If a small amount of boron is mixed with silicon, the mixture is a good conductor of electric current. Silicon can be cut into wafers, and used to make computer chips. 6.1

© Copyright Pearson Prentice Hall Slide 24 of 28 Section Quiz -or- Continue to: Launch: Assess students’ understanding of the concepts in Section Section Assessment 6.1

© Copyright Pearson Prentice Hall Slide 25 of 28 1.The modern periodic table has elements arranged in order of a.colors. b.melting and boiling points. c.increasing atomic mass. d.increasing atomic number. 6.1 Section Quiz

© Copyright Pearson Prentice Hall Slide 26 of Mendeleev arranged the elements in his periodic table in order of increasing a.atomic number. b.number of protons. c.number of electrons. d.atomic mass 6.1 Section Quiz

© Copyright Pearson Prentice Hall Slide 27 of Which one of the following is NOT a general property of metals? a.ductility b.malleability c.having a high luster d.poor conductor of heat and electricity 6.1 Section Quiz

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