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Pretest
1. Which of the following is a symbol for an element?
a. Aluminumb. Alc. ald. AL
2. Is flammability a physical property or a chemical property?
3. What happens to the composition of matter during a physical change?
Chapter 5
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Pretest (continued)
4. What does the atomic number of an element represent?
5. Different isotopes of an element have different numbers of
a. neutrons. b. electrons. c. protons. d. nuclei.
Chapter 5
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Pretest (continued)
6. True or False: Electrons in atoms occupy orbitals in energy levels.
7. Which element is more reactive, oxygen or nitrogen?
Chapter 5
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Interest Grabber
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.
Section 5.1
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Reading Strategy
Summarizing
Section 5.1
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)
Figure 3
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Interest Grabber
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.
Section 5.2
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Reading Strategy
Previewing
Section 5.2
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
Figure 7
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Isotopes of Chlorine Figure 9
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Interest Grabber
Other Periodic TablesMost 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?
Section 5.3
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Reading Strategy
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.
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.
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Reading Strategy
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.
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.
Pretest Answers
1. Which of the following is a symbol for an element?
a. Aluminumb. Alc. ald. AL
2. Is flammability a physical property or a chemical property?
3. What happens to the composition of matter during a physical change?
Chapter 5
Click the mouse button to display the answers.
a chemical property
It remains the same.
Chapter 5Pretest Answers (continued)
Click the mouse button to display the answers.
4. What does the atomic number of an element represent?
5. Different isotopes of an element have different numbers of
a. neutrons. b. electrons. c. protons. d. nuclei.
the number of protons in an atom of the element
Chapter 5Pretest Answers (continued)
Click the mouse button to display the answers.
6. True or False: Electrons in atoms occupy orbitals in energy levels.
7. Which element is more reactive, oxygen or nitrogen?
oxygen
Interest GrabberAnswers
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.
Section 5.1
Interest GrabberAnswers
Designs will vary, but students should include all the information supplied.
Section 5.2
Interest GrabberAnswers
Section 5.3
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.)
Chapter 5Go Online
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.
