Organizing the Elements 6.1

Mendeleev’s Periodic Table 6.1 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.

Mendeleev’s Periodic Table 6.1 Mendeleev’s Periodic Table An Early Version of Mendeleev’s Periodic Table In this early version of Mendeleev’s periodic table, the rows contain elements with similar properties. Observing A fourth element is grouped with chlorine (Cl), bromine (Br), and (I) iodine. What is this element’s symbol?

The Periodic Law How is the modern periodic table organized? 6.1

6.1 The Periodic Law In the modern periodic table, elements are arranged in order of increasing atomic number. In the modern periodic table, the elements are arranged in order of increasing atomic number. Interpreting Diagrams How many elements are there in the second period?

6.1 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.

Metals, Nonmetals, and Metalloids 6.1 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.

Metals, Nonmetals, and Metalloids 6.1 Metals, Nonmetals, and Metalloids Metals, Metalloids, and Nonmetals in the Periodic Table One way to classify elements in the periodic table is as metals, nonmetals, and metalloids. Inferring What is the purpose for the black stair-step line?

Metals, Nonmetals, and Metalloids 6.1 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.

Metals, Nonmetals, and Metalloids 6.1 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.

Section Assessment 6.1

1. The modern periodic table has elements arranged in order of 6.1 Section Quiz 1. The modern periodic table has elements arranged in order of colors. melting and boiling points. increasing atomic mass. increasing atomic number.

6.1 Section Quiz 2. Mendeleev arranged the elements in his periodic table in order of increasing atomic number. number of protons. number of electrons. atomic mass

3. Which one of the following is NOT a general property of metals? 6.1 Section Quiz 3. Which one of the following is NOT a general property of metals? ductility malleability having a high luster poor conductor of heat and electricity

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