1. The Periodic Table Preview Understanding Concepts Reading Skills
Interpreting Graphics

2. Understanding Concepts
1. What group of elements is the least reactive?
A. halogens
B. alkali metals
C. noble gases
D. semiconductors

3. Understanding Concepts
1. What group of elements is the least reactive?
A. halogens
B. alkali metals
C. noble gases
D. semiconductors

4. Understanding Concepts, continued
2. What does the symbol Li+ represent?
F. a lithium isotope
G. a lithium atom
H. a lithium ion
I. a lithium molecule

5. Understanding Concepts, continued
2. What does the symbol Li+ represent?
F. a lithium isotope
G. a lithium atom
H. a lithium ion
I. a lithium molecule

6. Understanding Concepts, continued
3. What information about an element is most crucial for locating that element in the periodic table?
A. the element’s atomic number
B. the element’s electric charge
C. the element’s most common isotope
D. the number of orbitals the element has

7. Understanding Concepts, continued
3. What information about an element is most crucial for locating that element in the periodic table?
A. the element’s atomic number
B. the element’s electric charge
C. the element’s most common isotope
D. the number of orbitals the element has

8. Understanding Concepts, continued
4. Carbon, whose atomic number is 6, has four valence electrons. Sulfur’s atomic number is 16, and sulfur is located two columns to the right of carbon and one row down on the periodic table. How many valence electrons does sulfur have?
F H. 7
G. 6 I. 14

9. Understanding Concepts, continued
4. Carbon, whose atomic number is 6, has four valence electrons. Sulfur’s atomic number is 16, and sulfur is located two columns to the right of carbon and one row down on the periodic table. How many valence electrons does sulfur have?
F H. 7
G. 6 I. 14

10. Understanding Concepts, continued
5. Why are the elements in Group 1 the most reactive?

11. Understanding Concepts, continued
Why are the elements in Group 1 the most reactive?
Answer: They have only one valence electron, which is easily shared with any element with a partially filled electron orbital.

12. Understanding Concepts, continued
If the element ununoctium is ever synthesized,it will be located directly under radon, xenon and krypton on the periodic table. What would ununoctium’s atomic number be? Predict ununoctium’s properties.

13. Understanding Concepts, continued
If the element ununoctium is ever synthesized,it will be located directly under radon, xenon and krypton on the periodic table. What would ununoctium’s atomic number be? Predict ununoctium’s properties.
Answer: 118; inert, nonreactive, full electron shells

14. Understanding Concepts, continued
7. What group of elements has some properties of metals and some properties of nonmetals? How does the periodic table reflect this fact?

15. Understanding Concepts, continued
What group of elements has some properties of metals and some properties of nonmetals? How does the periodic table reflect this fact?
Answer: Metalloids, or semiconductors; they are located on the border between the metals and nonmetals.

16. MENDELEEV’S DISCOVERY
Reading Skills
MENDELEEV’S DISCOVERY
On March 6, 1869, Mendeleev made a formal presentation to introduce his new periodic table. He explained that elements that have similar chemical properties either have atomic masses that are nearly the same value (as have Os, Ir and Pt) or have atomic masses that increase regularly (as have K, Rb, and Cs). Arranging the elements in rows, within which they are in order of their atomic masses, creates columns corresponding to electron valencies. The elements whose particles are the most widely diffused—gases—have small atomic masses. Mendeleev told scientists that they should expect the discovery of some new elements. Two of the elements whose existence he predicted are gallium and germanium. Based on their location in the periodic table (directly below aluminum and silicon), he accurately predicted their atomic masses to be between 65 and 75.

17. Reading Skills, continued
Based on the passage, what does the word diffused mean?
A. close together
B. spread apart
C. a high temperature
D. a low temperature

18. Reading Skills, continued
Based on the passage, what does the word diffused mean?
A. close together
B. spread apart
C. a high temperature
D. a low temperature

19. Reading Skills, continued
What is one of the widely diffused elements Mendeleev was likely referring to in his presentation?
F. bromine
G. iodine
H. helium
I. uranium

20. Reading Skills, continued
What is one of the widely diffused elements Mendeleev was likely referring to in his presentation?
F. bromine
G. iodine
H. helium
I. uranium

21. Reading Skills, continued
10. When Mendeleev predicted the existence of the elements gallium and germanium, he temporarily named these elements ekaaluminum and ekasilicon. What does the prefix eka- mean, in terms of the layout of the periodic table?

22. Reading Skills, continued
10. When Mendeleev predicted the existence of the elements gallium and germanium, he temporarily named these elements ekaaluminum and ekasilicon. What does the prefix eka- mean, in terms of the layout of the periodic table?
Answer: In the same column, because of similar properties; but one row down, because of a higher atomic number.

23. Interpreting Graphics
The graphic below shows the bonding of sodium and chlorine to form sodium chloride, NaCl. Use this graphic to answer questions 11 and 12.

24. Interpreting Graphics, continued
11. How many total valence electrons do the two atoms have?
A. 0 C. 7
B. 1 D. 8

25. Interpreting Graphics, continued
11. How many total valence electrons do the two atoms have?
A. 0 C. 7
B. 1 D. 8

26. Interpreting Graphics, continued
12. What is the mass of one mole of NaCl molecules?
F. 28 g H × 1025 g
G. 58 g I × 1025 g

27. Interpreting Graphics, continued
12. What is the mass of one mole of NaCl molecules?
F. 28 g H × 1025 g
G. 58 g I × 1025 g

28. Interpreting Graphics, continued
The graphic below shows the upper right segment of the periodic table. Use this graphic to answer questions 13–15.

29. Interpreting Graphics, continued
13. Which pair of elements would most likely have a similar arrangement of outer electrons and have similar chemical behaviors?
A. boron and aluminum C. carbon and nitrogen
B. helium and fluorine D. chlorine and oxygen

30. Interpreting Graphics, continued
13. Which pair of elements would most likely have a similar arrangement of outer electrons and have similar chemical behaviors?
A. boron and aluminum C. carbon and nitrogen
B. helium and fluorine D. chlorine and oxygen

31. Interpreting Graphics, continued
14. What is the atomic mass of helium?

32. Interpreting Graphics, continued
What is the atomic mass of helium?
Answer: 4.00 u

33. Interpreting Graphics, continued
15. How many neutrons does the average helium atom contain?

34. Interpreting Graphics, continued
How many neutrons does the average helium atom contain?
Answer: 2