Organizing the Elements

Transcription

1 Organizing the Elements In a self-service store, the products are grouped according to similar characteristics. With a logical classification system, finding and comparing products is easy. You will learn how elements are arranged in the periodic table and what that arrangement reveals about the elements. 1 of 28

2 Organizing the Elements > Searching For an Organizing Principle Searching For an Organizing Principle How did chemists begin to organize the known elements? 2 of 28

3 Organizing the Elements > Searching For an Organizing Principle Chemists used the properties of elements to sort them into groups. 3 of 28

4 Organizing the Elements > Searching For an Organizing Principle Chlorine, bromine, and iodine have very similar chemical properties. 4 of 28

5 Organizing the Elements > Mendeleev s Periodic Table Mendeleev s Periodic Table How did Mendeleev organize his periodic table? 5 of 28

6 Organizing the Elements > Mendeleev s Periodic Table Mendeleev arranged the elements in his periodic table in order of increasing atomic mass. The periodic table can be used to predict the properties of undiscovered elements. 6 of 28

7 Organizing the Elements > Mendeleev s Periodic Table An Early Version of Mendeleev s Periodic Table 7 of 28

8 Organizing the Elements > The Periodic Law The Periodic Law How is the modern periodic table organized? 8 of 28

9 Organizing the Elements > The Periodic Law In the modern periodic table, elements are arranged in order of increasing atomic number. 9 of 28

10 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. The properties of the elements within a period change as you move across a period from left to right. The pattern of properties within a period repeats as you move from one period to the next. 10 of 28

11 Organizing the Elements > Metals, Nonmetals, and Metalloids Metals, Nonmetals, and Metalloids What are three broad classes of elements? 11 of 28

12 Organizing the Elements > Metals, Nonmetals, and Metalloids Metals, Metalloids, and Nonmetals in the Periodic Table 12 of 28

13 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. 13 of 28

14 Organizing the Elements > Metals, Nonmetals, and Metalloids Uses of Iron, Copper, and Aluminum 14 of 28

15 Organizing the Elements > Metals, Nonmetals, and Metalloids Uses of Iron, Copper, and Aluminum 15 of 28

16 Organizing the Elements > Metals, Nonmetals, and Metalloids Uses of Iron, Copper, and Aluminum 16 of 28

17 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. 17 of 28

18 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. 18 of 28

19 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. 19 of 28