Chapter+7+notes+2021

Ion Formation

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Table of Contents

Chapter 7 - Ionic Bonding ........................................................................................................................................ 3
7.1 Ions ..................................................................................................................................................................................... 4
Formation of Ions Worksheet ............................................................................................................................................ 6
7.2 Ionic Bonds and Ionic Compounds............................................................................................................................. 7
Forming Ionic Compounds worksheet ............................................................................................................................ 9
7.1/7.2 Worksheet ............................................................................................................................................................................................... 10

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Chapter 7 - Ionic Bonding

7.1 – Ions
Objectives

• Determine the number of valence electrons in an atom of a representative element
• Explain the octet rule

• Describe how cations form

• Explain how anions form

Vocabulary • octet rule
• halide ions
• valence electrons
• electron dot structures

7.2 – Ionic Bonds and Ionic Compounds
Objectives

• Explain the electrical charge of an ionic compound
• Describe three properties of ionic compounds

Vocabulary • chemical formula
• formula unit
• ionic compounds
• ionic bonds

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7.1 Ions

Lesson Summary - After reading Lesson 7.1, fill in the following statements.

Valence Electrons

Valence electrons are the electrons in the ________________ occupied energy level and are involved in ion
formation.

For a representative element, the group number equals the number of ______________ electrons
the atom contains.
An electron dot structure shows the ________________ of the element and its valence electrons.
Atoms tend to _________ or _________ the number of electrons that will provide the atom with a noble gas
electron configuration.

Formation of Cations

Cations are ________________ charged ions formed when an atom ___________ one or more valence electrons.
Atoms and the cations formed from them have __________________ properties.
Elements in Group 1 form cations with a charge of ___, and those in Group 2 form cations with a charge of ___.
Many ________________ metals form more than one cation and do not follow the ___________ rule.

Formation of Anions

Anions are ___________________ charged ions formed when an atom ___________ one or more valence electrons.
Commonly, the name of an anion ________ in -ide.
Anions form from ___________________ elements.
The anions formed from halogens are known as _______________.

Valence Electrons

1. What are valence electrons?

2. The valence electrons largely determine the of an element and are usually the
only electrons used in .

3. Is the following sentence true or false? The group number of a representative element in the periodic table is
related to the number of valence electrons it has. _____________

4. What is an electron dot structure?

5. Draw the electron dot structure for each of the following atoms.

Ar Ca I

a. argon b. calcium c. iodine

6. What is the octet rule?

7. Metallic atoms tend to valence electrons to produce a positively charged ion. Most

nonmetallic atoms achieve a complete octet by gaining or ____________________ electrons.

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Formation of Cations

8. Using your periodic table, write the electron configurations for these metals, and circle the electrons lost when
each metal forms a cation.

a. Mg b. Al _____________________ c. K _________________________

Match the noble gas with its electron configuration.

9. argon a. 1s2
10. helium b. [He]2s22p6
11. neon c. [Ne]3s23p6
12. krypton d. [Ar]3d104s24p6

13. What is the electron configuration called that has 8 electrons in the outer energy level and all of the orbitals
filled?

14. Write the electron configuration for zinc.

15. Fill in the electron configuration diagram for the copper(I) ion.

Energy level

Copper atom Copper (I) ion
Cu Cu+

Formation of Anions

16. Atoms of most nonmetallic elements achieve noble-gas electron configurations by

gaining electrons to become , or negatively charged ions.

17. What property of nonmetallic elements makes them more likely to gain electrons than lose electrons?

18. True or false? Elements of the halogen family lose one electron to become halide ions. ____________

19. How many electrons will each element gain in forming an ion?

a. nitrogen b. oxygen c. sulfur d. bromine

20. Write the symbol and electron configuration for each ion from Question 19, and name the noble gas with the
same configuration.

a. nitride

b. oxide

c. sulfide

d. bromide

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Formation of Ions Worksheet

1. What are the names of the two elements shown?
______________________________________________________________________________________________
2. Are the elements shown on the left sides of the two equations neutral? How can you tell?
______________________________________________________________________________________________
3. What is the name for the energy needed to remove electrons from an atom, such as the Ca atom shown?
______________________________________________________________________________________________
4. What kind of charge does the Ca atom take on as a result of the reaction? What is the name for an ion with that kind
of charge?
______________________________________________________________________________________________
5. What kind of charge does the O atom take on as a result of the reaction? What is the name for an ion with that kind of
charge?
______________________________________________________________________________________________
6. Is the outer electron configuration of the Ca atom before the reaction a very stable one? How can you tell?
______________________________________________________________________________________________
7. Is the outer electron configuration of the O atom before the reaction a very stable one? How can you tell?
______________________________________________________________________________________________
8. Is the outer electron configuration of the Ca ion after the reaction a very stable one? How can you tell?
______________________________________________________________________________________________
9. Is the outer electron configuration of the O ion after the reaction a very stable one? How can you tell?
______________________________________________________________________________________________
10. What is the electron configuration of the Ca ion? What neutral atom has the same configuration, and in what
chemical family is it located in the periodic table?
______________________________________________________________________________________________
11. What is the electron configuration of the O ion? What neutral atom has the same configuration, and in what chemical
family is it located in the periodic table?
______________________________________________________________________________________________

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7.2 Ionic Bonds and Ionic Compounds

Lesson Summary - After reading the section, fill in the following statements.

Formation of Ionic Compounds An ionic compound is made up of __________ and cations and has an

overall charge of __________.
The __________________ attraction between an anion and a cation is an ionic bond.
The representative unit of an ionic compound is its __________________________.
A formula unit of an ionic compound shows the ions in their lowest, ______________________ ratio.

Properties of Ionic Compounds Ionic compounds have characteristic properties that distinguish them from

other substances.
Most ionic compounds are ___________________ solids at room temperature.
In general, ionic compounds have __________ melting points because the ions have a strong attraction for one
another.
Ionic compounds conduct an electric current when ________________ or in an ______________ solution
because the ions are then free to _____________.

Formation of Ionic Compounds

1. What is an ionic bond?

2. In an ionic compound, the charges of the and must balance to
produce an electrically
substance.

3. Complete the electron dot structures below to show how beryllium fluoride (BeF2) is formed. Use the diagram
on page 203 as a model.

4. Why do beryllium and fluorine combine in a 1:2 ratio?

5. A chemical formula shows the types and of atoms in the smallest representative unit of a
substance.

6. List the numbers and types of atoms represented by these chemical formulas.

a. Fe2O3
b. KMnO4
c. CH3
d. NH4NO3

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7. What is a formula unit?
8. Explain why the ratio of magnesium ions to chloride ions in MgCl2 is 1:2.
9. Describe the structure of ionic compounds.

Properties of Ionic Compounds

10. Most ionic compounds are at room temperature.

11. T or false? Ionic compounds generally have low melting points. __________

12. Circle the letter of each statement that is true about ionic compounds.
a. When dissolved in water, ionic compounds can conduct electricity.
b. When melted, ionic compounds do not conduct electricity.
c. Ionic compounds have very unstable structures.
d. Ionic compounds are electrically neutral.

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Forming Ionic Compounds worksheet

1. How many valence electrons does a neutral magnesium (Mg) atom have? __________________________________
2. What is the charge on a magnesium ion? What does magnesium have to do to form such an ion, and

why does it tend to do so?
______________________________________________________________________________________________
______________________________________________________________________________________________
3. How many valence electrons does a single neutral chlorine (Cl) atom have? ________________________________
4. What is the charge on a chloride ion? What does chlorine have to do to form such an ion, and why
does it tend to do so?
______________________________________________________________________________________________
______________________________________________________________________________________________
5. How many magnesium atoms and how many chlorine atoms react to form one formula unit of
magnesium chloride? Why? What is the formula of magnesium chloride?
______________________________________________________________________________________________
______________________________________________________________________________________________
6. What kind of compound is magnesium chloride? What happens to electrons during the formation

of the compound? What holds the atoms together in the compound?
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
7. What is the formula of the ionic compound formed by magnesium and sulfur (S) atoms? Explain
why, in terms of electron transfer, stability, and overall charge.
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________

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7.1/7.2 Worksheet __12. Which of the following elements forms an ion with a 1–

__1. The Lewis dot symbol for a lead atom is:

charge?

A. B. C. D. E. A. F B. O C. K D. Na

__2. The Lewis dot symbol for the S2- ion is: __13. What is the formula of the ion formed when tin

2- achieves a noble gas electron configuration?
A. Sn+1 B. Sn+2 C. Sn+3 D. Sn+4
A. B. C. S2- D. E.

__3. The Lewis dot symbol for the chloride ion is: __14. What is the formula of the ion formed when

phosphorus achieves a noble gas electron configuration?
A. P+1 B. P+3 C. P-3 D. P-1
A. B. C.

D. E. __15. How does oxygen obey the octet rule when reacting to
form compounds?
__4. The Lewis dot symbol for the calcium ion is: A. It gains electrons.
B. It gives up electrons.
A. B. C. D. Ca2+ E. Ca C. It does not change its number of electrons.
D. Oxygen does not obey the octet rule.

__5. Select the element whose Lewis symbol is correct. __16. 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.

__6. Select the element whose Lewis symbol is correct. __17. Which of the following is true about an ionic
compound?
__7. Select the correct formula for a compound formed from A. The chemical formula shows the atoms in a molecule.
B. The formula unit gives the number of each type of ions in
calcium and chlorine. a crystal.
C. It is composed of anions and cations and yet it is
A. CaCl B. CaCl2 C. Ca2Cl electrically neutral.
D. The chemical formula shows the ions in a molecule.
D. Ca2Cl2 E. CaCl3

__8. How does calcium obey the octet rule when reacting to __18. How many valence electrons are transferred from the
form compounds?
A. It gains electrons. nitrogen atom to potassium in the formation of the compound
B. It gives up electrons.
C. It does not change its number of electrons. potassium nitride?
D. Calcium does not obey the octet rule.
A. 0 B. 1 C. 2 D. 3

__19. How many valence electrons are transferred from the

calcium atom to each iodine atom in the formation of the

__9. What is the electron configuration of the calcium ion? compound calcium iodide?
A. 1s22s22p63s23p6
B. 1s22s22623s23p64s2 A. 0 B. 1 C. 2 D. 3
C. 1s22s22p63s23p64s24p6
D. 1s22s22p63s23p63d2 __20. What is the formula unit of aluminum oxide?

A. AlO B. Al2O C. Al3O2 D.

Al2O3

__10. What is the charge on the strontium ion? __21. Ionic compounds are normally in which physical state

A. 2– B. 1– at room temperature?

C. 1+ D. 2+ A. solid B. liquid C. gas D.

__11. What is the formula of the ion formed when potassium plasma

achieves noble-gas electron configuration?
A. K+1 B. K+2
C. K-1 D. K-2

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