Identify the choice that best completes the statement or answers the question.
1. Which of the following is true about the composition of ionic compounds?
a. They are composed of anions and cations.
b. They are composed of anions only.
c. They are composed of cations only.
d. They are formed from two or more nonmetallic elements.
2. If sodium has a +1 charge and the sulfate ion has a -2 charge, what is the formula for sodium sulfate?
a. NaSO c. Na(SO )
b. Na SO d. Na (SO )
3. An atom in the ground state contains a total of 5 electrons, 5 protons, and 5 neutrons. Which Lewis
electron-dot diagram represents this atom?
4. How many valence electrons are in a silicon atom?
a. 2 c. 6
b. 4 d. 8
5. Which Lewis electron-dot diagram correctly represents a hydroxide ion?
6. How are chemical formulas of ionic compounds containing two elements generally written?
a. cation on left, anion on right
b. anion on left, cation on right
c. Roman numeral first, then anion, then cation
d. subscripts first, then ions
7. Which of the following pairs of elements is most likely to form an ionic compound?
a. magnesium and fluorine
b. nitrogen and sulfur
c. oxygen and chlorine
d. sodium and aluminum
8. Which of the following compounds contains the Mn ion?
a. MnS c. Mn O
b. MnBr d. MnO
9. Which Lewis electron-dot diagram represents calcium oxide?
10. How many valence electrons are transferred from the nitrogen atom to potassium in the formation of the
compound potassium nitride?
a. 0 c. 2
b. 1 d. 3
11. How many electrons does nitrogen gain in order to achieve a noble-gas electron configuration?
a. 1 c. 3
b. 2 d. 4
12. Which Lewis electron-dot diagram is correct for CO2?
13. When Group 2A elements form ions, they ____.
a. lose two protons c. lose two electrons
b. gain two protons d. gain two electrons
14. How many valence electrons are in an atom of phosphorus?
a. 2 c. 4
b. 3 d. 5
15. What is the net charge of the ionic compound calcium fluoride?
a. 2– c. 0
b. 1– d. 1
16. Which of the following is NOT a cation?
a. iron(III) ion c. Ca
b. sulfate d. mercurous ion
17. What is the oxidation number (cahrge it carries) of the strontium ion?
a. 2– c. 1
b. 1– d. 2
18. Why do atoms share electrons in covalent bonds?
a. to become ions and attract each other
b. to attain a noble-gas electron configuration
c. to become more polar
d. to increase their atomic numbers
19. Given a formula for oxygen:
What type of electrons are represented by A?
a. Lone Pairs b. Bond Pairs
20. Usint the diagram in #19 above, hoe many electrons are contained in the bond pairs of electrons?
a. 2 c. 6
b. 4 d. 8
21. Which of the following occurs in an ionic bond?
a. Oppositely charged ions attract.
b. Two atoms share two electrons.
c. Two atoms share more than two electrons.
d. Like-charged ions attract.
22. Under what conditions can potassium bromide conduct electricity?
a. only when melted
b. only when dissolved
c. only when it is in crystal form
d. only when melted or dissolved in water
23. Which term indicates how strongly an atom attracts the electrons in a chemical bond?
a. alkalinity c. electronegativity
b. atomic mass d. activation energy
24. How does calcium obey the octet rule when reacting to form compounds?
a. It gains electrons.
b. It gives up electrons.
c. It does not change its number of electrons.
d. Calcium does not obey the octet rule.
25. Which of the following elements does NOT form an ion with a charge of 1 ?
a. fluorine c. potassium
b. hydrogen d. sodium
26. A molecule with a single covalent bond is ____.
a. CO c. CO
b. Cl d. N
27. Which of the following is NOT a characteristic of most ionic compounds?
a. They are solids.
b. They have low melting points.
c. When melted, they conduct an electric current.
d. They are composed of metallic and nonmetallic elements.