Transcript Chapter 5

Pretest
Chapter 5
1. Which of the following is a symbol for an element?
a.
b.
c.
d.
Aluminum
Al
al
AL
2. Is flammability a physical property or a chemical property?
3. What happens to the composition of matter during a
physical change?
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Pretest (continued)
Chapter 5
4. What does the atomic number of an element represent?
5. Different isotopes of an element have different numbers of
a.
b.
c.
d.
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neutrons.
electrons.
protons.
nuclei.
Pretest (continued)
Chapter 5
6. True or False: Electrons in atoms occupy orbitals in
energy levels.
7. Which element is more reactive, oxygen or nitrogen?
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Interest Grabber
Section 5.1
A Logical Organization
The ability to organize information in a logical way is a
valuable skill. Have you ever noticed the way shoeboxes
are arranged in a shoe store? Sometimes the shoeboxes
are separated into a series of vertical stacks (or columns)
by style. Within each stack, the shoes are arranged by size.
1. How is this system of organizing shoes useful?
2. Explain how a calendar organizes time.
3. Think of another example of how information
is organized.
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Reading Strategy
Section 5.1
Summarizing
a. Mendeleev arranged the elements in order of increasing mass so that
elements with similar properties were in the same column.
b. Mendeleev used the properties of existing elements to predict properties
of undiscovered elements.
c. The close match between Mendeleev’s predictions and the actual
properties of new elements showed how useful his periodic table could be.
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Mendeleev’s Table of
Elements (1872)
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Figure 3
Interest Grabber
Section 5.2
Displaying Information About Elements
For each element there are many useful pieces of
information, such as its name, symbol, atomic number, and
state at room temperature. Look at the information for the
element copper. There are different ways to display this
information. On a piece of paper, design a way to organize
the information inside a small square. You can use devices
such as color to help fit the information in the square. Think
about how this square will fit in a table that includes all the
elements.
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Reading Strategy
Section 5.2
Previewing
a. and c. Students might ask the meaning of the term atomic number, why
two series of elements are placed below the main body of the table,
why there are two numbering systems for the columns, or why
Period 7 is incomplete.
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Periodic Table of
Elements
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Figure 7
Isotopes of Chlorine
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Figure 9
Interest Grabber
Section 5.3
Other Periodic Tables
Most periodic tables of the elements
have the same general organization
as the one in your textbook.
However, there are some periodic
tables that look quite different.
Look at Theodore Benfey’s version
of a periodic table, which he
made in 1960.
1. How is it similar to the
periodic table in your book?
2. How is it different from the
periodic table in your book?
3. Is there any advantage to
Benfey’s arrangement of
the elements?
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Reading Strategy
Section 5.3
Monitoring Your Understanding
Possible answers:
a. Magnesium plays a key role in the production of sugar in plants. Mixtures of
magnesium and other metals can be as strong as steel, but much lighter.
b. Aluminum is the most abundant metal in Earth’s crust. Much less energy is
needed to purify recycled aluminum than to extract aluminum from bauxite.
c. Chlorine is a highly reactive, nonmetal gas that is used to kill bacteria in water.
Go to section
Reading Strategy
Section 5.3
Monitoring Your Understanding
Possible answers:
a. Magnesium plays a key role in the production of sugar in plants. Mixtures of
magnesium and other metals can be as strong as steel, but much lighter.
b. Aluminum is the most abundant metal in Earth’s crust. Much less energy is
needed to purify recycled aluminum than to extract aluminum from bauxite.
c. Chlorine is a highly reactive, nonmetal gas that is used to kill bacteria in water.
Go to section
Pretest Answers
Chapter 5
1. Which of the following is a symbol for an element?
a.
b.
c.
d.
Aluminum
Al
al
AL
2. Is flammability a physical property or a chemical property?
a chemical property
3. What happens to the composition of matter during a
physical change?
It remains the same.
Click the mouse button to display the answers.
Pretest Answers
Chapter 5
(continued)
4. What does the atomic number of an element represent?
the number of protons in an atom of the element
5. Different isotopes of an element have different numbers of
a.
b.
c.
d.
neutrons.
electrons.
protons.
nuclei.
Click the mouse button to display the answers.
Pretest Answers
Chapter 5
(continued)
6. True or False: Electrons in atoms occupy orbitals in
energy levels.
7. Which element is more reactive, oxygen or nitrogen?
oxygen
Click the mouse button to display the answers.
Interest Grabber
Section 5.1
Answers
1. How is this system of organizing shoes useful?
This system makes it much easier for the salesperson to
find the right shoe quickly.
2. Explain how a calendar organizes time.
A calendar separates a year into months, then months
into weeks, and then weeks into days.
3. Think of another example of how information is
organized.
Answers will vary, but may include a class schedule,
train or bus schedule, or the aisles in a supermarket.
Interest Grabber
Section 5.2
Answers
Designs will vary, but students should include all the
information supplied.
Interest Grabber
Section 5.3
Answers
1. How is it similar to the periodic table in your book?
Both tables have the elements arranged in order of increasing
atomic number and in groups with similar properties.
2. How is it different from the periodic table in your book?
In Benfey’s table the elements are arranged in a spiral instead
of columns and rows. Benfey’s table contains no data except
the symbols of the elements.
3. Is there any advantage to Benfey’s arrangement of the
elements?
The lanthanides and actinides are more closely connected to
the other elements and it is clearer that hydrogen has the
atomic number 1. (The most significant advantage is that the
spiral format shows the connection between periods and
atomic structure.)
Go Online
Chapter 5
Self-grading assessment
Articles on elements
For links on the periodic table, go to www.SciLinks.org
and enter the Web Code as follows: ccn-1051.
For links on periodic law, go to www.SciLinks.org and
enter the Web Code as follows: ccn-1052.