Organizing the Elements

Transcription

1 Organizing the Elements 1 of 28 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. 2 of 28 1

2 Organizing the Elements > Searching For an Organizing Principle Searching For an Organizing Principle How did chemists begin to organize the known elements? 3 of 28 Organizing the Elements > Searching For an Organizing Principle Chemists used the properties of elements to sort them into groups. 4 of 28 2

3 Organizing the Elements > Searching For an Organizing Principle Chlorine, bromine, and iodine have very similar chemical properties. 5 of 28 Organizing the Elements > Mendeleev s Periodic Table Mendeleev s Periodic Table How did Mendeleev organize his periodic table? 6 of 28 3

4 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. 7 of 28 Organizing the Elements > Mendeleev s Periodic Table An Early Version of Mendeleev s Periodic Table 8 of 28 4

5 Organizing the Elements > The Periodic Law The Periodic Law How is the modern periodic table organized? 9 of 28 Organizing the Elements > The Periodic Law In the modern periodic table, elements are arranged in order of increasing atomic number. 10 of 28 5

6 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. 11 of 28 Metals, Nonmetals, and Metalloids What are three broad classes of elements? 12 of 28 6

7 Three classes of elements are metals, nonmetals, and metalloids. Across a period, the properties of elements become less metallic and more nonmetallic. 13 of 28 Metals, Metalloids, and Nonmetals in the Periodic Table 14 of 28 7

8 Metals, Metalloids, and Nonmetals in the Periodic Table 15 of 28 Metals, Metalloids, and Nonmetals in the Periodic Table 16 of 28 8

9 Metals, Metalloids, and Nonmetals in the Periodic Table 17 of 28 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. 18 of 28 9

10 Uses of Iron, Copper, and Aluminum 19 of 28 Uses of Iron, Copper, and Aluminum 20 of 28 10

11 Uses of Iron, Copper, and Aluminum 21 of 28 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. 22 of 28 11

12 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. 23 of 28 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. 24 of 28 12