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6.1
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
Organizing the Elements >
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Searching For an Organizing Principle
Searching For an Organizing Principle
How did chemists begin to organize the known elements?
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Organizing the Elements > Searching For an Organizing Principle
Chemists used the properties of elements to sort them into groups.
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Organizing the Elements > Searching For an Organizing Principle
Chlorine, bromine, and iodine have very similar chemical properties.
Organizing the Elements >
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Mendeleev’s Periodic Table
Mendeleev’s Periodic Table
How did Mendeleev organize his periodic table?
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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.
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Organizing the Elements > Mendeleev’s Periodic Table
An Early Version of Mendeleev’s Periodic Table
Organizing the Elements >
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The Periodic Law
The Periodic Law
How is the modern periodic table organized?
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Organizing the Elements > The Periodic Law
In the modern periodic table,
elements are arranged in order of increasing atomic number.
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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 periodrepeats as you move from one period to the next.
Organizing the Elements >
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Metals, Nonmetals, and Metalloids
Metals, Nonmetals, and Metalloids
What are three broad classes of elements?
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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.
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Organizing the Elements > Metals, Nonmetals, and Metalloids
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Organizing the Elements > Metals, Nonmetals, and Metalloids
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Organizing the Elements > Metals, Nonmetals, and Metalloids
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Organizing the Elements > Metals, Nonmetals, and Metalloids
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Organizing the Elements > Metals, Nonmetals, and Metalloids
Metals
Metals are good conductors of heat and
electric current.
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80% of elements are metals.•
Metals have a high luster, are ductile, and are malleable.Slide 19 of 28
Organizing the Elements > Metals, Nonmetals, and Metalloids
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Organizing the Elements > Metals, Nonmetals, and Metalloids
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Organizing the Elements > Metals, Nonmetals, and Metalloids
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Organizing the Elements > Metals, Nonmetals, and Metalloids
Nonmetals
In general, nonmetals are poor conductors of heat and electric current.
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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.Slide 23 of 28
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.
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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.
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Section Quiz
-or-Continue to: Launch:
Assess students’ understanding of the concepts in Section
Section Assessment
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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.
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2. 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
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3. 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
