Name_________________________________ Hour_______ Date____________
Ions, Ionic Compounds, and Covalent Molecules
Use the data from the “List of Common Ions” page and the two tables below to answer the questions on the
back of this sheet! You must use data to support your answers.
Table 1. Determining ion charge
Element
# of valence e-
What would do
for 8 valence e-
Charge
Ion
Selenium
6
Gain 2 e-
-2
Se2-
Beryllium
2
Lose 2 e-
+2
Be2+
Phosphorus
5
Gain 3 e-
-3
P3-
Rubidium
1
Lose 1 e-
+1
Rb+
Chlorine
7
Gain 1 e-
-1
Cl-
Boron
5
Gain 3 e-
-3
B3-
Hydrogen
1
Lose 1 e-
+1
H+
Table 2. Ionic compound formulas and names
Cation
Anion
Formula
Name
Magnesium
Mg2+
Sulfur
S2-
MgS
Magnesium sulfide
Potassium
K+
Carbonate
CO32-
K2CO3
Potassium carbonate
Calcium
Ca2+
Hydroxide
OH-
Ca(OH)2
Calcium hydroxide
Copper (II)
Cu2+
Chlorine
Cl-
CuCl2
Copper (II) chloride
Data analysis and model development: Ions and IONIC COMPOUNDS
When answering all of these questions, you MUST use data from the tables provided. The following is an acceptable
answer to the first question: monoatomic ions (such as Na+) are composed of an atom from one element whereas
polyatomic ions (such as CO32-) are composed of more than one atom from different elements. Na+ is composed of
one sodium atom whereas CO32- contains a carbon and oxygen atom. Na+ and CO32-are similar in that both contain an
uneven number of electrons and protons, resulting in a positive or negative charge.
Using list of common ions
1. What is similar and different between monoatomic and polyatomic ions?
2. What is different between cations and anions?
3. How can you determine the charge of a Type A element’s ion?
4. How are transition metals different than other elements in the periodic table in the ions they form?
5. What is different about naming a monoatomic and polyatomic ion?
Using Table 1 and Table 2 from the front page
6. What is the relationship between an element’s number of valence electrons and the charge developed when it is
an ion?
7. Why do metals lose electrons when forming an ion and nonmetals gain electrons to form an ion?
8. What patterns can you see in determining the formula of an ionic compound given the ions that compose it?
9. How do you name an ionic compound?
10. What are ionic compounds?
11. Write down 5 rules to determining ions, writing ionic compounds, and naming ionic compounds.
Data analysis and model development: Ions and COVALENT MOLECULES
When answering all of these questions, you MUST use data from the tables provided.
Lewis Structure: A Lewis structure is a way of showing the number of valence electrons each
element’s atoms have. Look at the table below to identify trends.
Octet Rule: Elements want to gain or lose electrons to have the same electron configuration
as the nearest noble gas. Thus, they want to have 8 valence electrons.
Figure 1. Trends in Lewis Structures
Figure 2. Listings of Electronegativities of Each Element
Figure 3. Determination of Bond Type Based on Electronegativity Difference
Table 1. Covalent molecule formulas and names
Element #1
Number of Single
Covalent bonds
Element #2
Formula
Name
Oxygen
Oxygen
Number of
Single Covalent
Bonds
2
2
Carbon
Hydrogen
4
1
CO2
H2O
1
Chlorine
1
HCl
4
Hydrogen
1
CH4
Carbon dioxide
Dihydrogen oxide
(water)
Hydrogen chloride
(hydrochloric acid)
Carbon
tertahydride
(methane)
Hydrogen
Carbon
Using Figure 1
1. What does each dot around the element symbol for a Lewis structure represent?
2. What do you notice about all of the elements in the same family (column)?
3. Looking at the halogen column, how many electrons does a halogen want to take or share in order to fulfill the
octet rule? How does the Lewis structure for all of the halogens show this?
4. An element can gain or lose electrons by forming bonds. When an element shares two valence electrons (one of
its own and one from another element) a single covalent bond is formed. How many single covalent bonds
would each halogen form?
5. How many single covalent bonds would all elements in the oxygen column form?
Using Figure 2
1. Metals give away electrons to non-metals when they form bonds; this bond is called an ionic bond. What do
you notice about the electronegativities of metals and non-metals?
2. Why isn’t the noble gas column on the table of Figure 2?
Using Figure 3
1. Using the difference in electronegativites found in Figure 3, explain why covalent bonds only occur between
nonmetals.
2. Using Figure 3, make a prediction about the difference between nonpolar covalent bonds and polar covalent
bonds.
3. What is the difference between a covalent bond and an ionic bond?
Using Table 1
1. What patterns can you identify between the number of covalent bonds each element in a covalent molecule can
make and the formula?
2. What patterns did you notice in the naming of covalent molecules?