Go Fish for an Ion: A Chemistry Card Game

Introduction

Learn the chemical formulas, names and charges of some common ions while having fun with this engaging chemistry card game.

Concepts

• Ion formulas
• Cations
• Chemical formulas
• Ion charges
• Anions
• Chemical names

Background

It is important for students in an introductory chemistry class to begin learning the language of chemistry. A good way to help students recognize and read chemical names, formulas, and equations is for them to learn the common ions. Ions are atoms or groups of atoms that have a net positive or negative charge. Once students become familiar with the names and formulas for common ions, they can begin to write chemical formulas and equations.

The playing cards in this game are specially designed to help students learn ion formulas, names, and charges while they play the game. The ion formulas on the front of the cards include both the symbol and the charge. It is important that students become familiar with seeing the chemical symbol together with the appropriate charge.

Each set of Go Fish for an Ion playing cards consists of 64 cards, with 10 different cations and 10 different anions. A cation is any atom or group of atoms with a net positive charge, such as Cu²⁺ or NH₄⁺. An anion is any atom or group of atoms with a net negative charge, such as O^2– or SO₄^2–. Atoms of metallic elements tend to form cations and atoms of nonmetallic elements tend to form anions.

For metal cations, the name of the ion is exactly the same as the name of the element. Thus a potassium atom (K) forms a potassium cation (K⁺) and a calcium atom (Ca) forms a calcium cation (Ca²⁺). The name of a nonmetal anion, on the other hand, is not the same as the element name. Instead, the name of the anion ends in –ide. Thus a sulfur atom (S) forms a sulfide anion (S^2–) and a chlorine atom (Cl) forms a chloride anion (Cl^–). The metals in Groups 1A, 2A and 3A of the periodic table lose electrons to form cations with 1+, 2+ and 3+ charges, respectively. Notice that the ionic charge is positive and is numerically equal to the group number. The transition metals, in contrast, may have more than one common ionic charge. For example, copper forms two common cations, Cu⁺ (copper(I)) and Cu²⁺ (copper(II)). The two metals in Group 14 or 4A of the periodic table, tin and lead, also have more than one common ionic charge, forming both the 2+ (Sn²⁺ and Pb²⁺) and 4+ (Sn⁴⁺ and Pb⁴⁺) cations.

There are two methods of naming cations with more than one common ionic charge. In the Stock system, a Roman numeral in parentheses is used as part of the name of the element to indicate the numerical value of the charge. For example, Cu⁺ is the copper(I) ion and is read as the “copper one” ion while Cu²⁺ is the copper(II) ion and is read as the a “copper two” ion. This system is the accepted standard for educational purposes at this current time. The older, Latin-based method of naming these cations is called the Classical system. This system uses a root word with different suffixes at the end of the word. The suffix –ous is used for the name of the cation with the lower of the two possible ionic charges while the suffix –ic is used with the higher of the two ionic charges. Using this system, Cu⁺ is the copper(I) cation and Cu²⁺ is the copper(II) cation.

Ions consisting of single atoms are called monatomic ions. Unlike the monatomic ions, polyatomic ions are covalently bonded groups of atoms that behave as a unit and carry a net charge. The nitrate anion, for instance, is composed of four atoms—one nitrogen atom and three oxygen atoms. The nitrate ion has a –1 charge and is written NO₃^–. Many polyatomic anion names end in –ite or –ate. However, there are two important exceptions to this rule—the cyanide anion (CN^–) and the hydroxide anion (OH^–), which both end in –ide. The most common polyatomic cation is NH₄⁺, which is called the ammonium ion.

Notice that there is a relationship between polyatomic ions for which there is an –ite/–ate pair, such as chlorite (ClO₂^–) and chlorate (ClO₃^–). The charge on each pair is the same; however, the –ite ending indicates one less oxygen atom than the –ate ending. In addition, notice hypochlorite (ClO^–), where the prefix hypo– indicates one less oxygen atom than the –ite ending and perchlorate (ClO₄^–), where the prefix per– indicates one more oxygen atom than the –ate ending.

The 64 playing cards in each Go Fish for an Ion deck provide an excellent starting point for students to learn names, formulas, and charges of the more common ions. The ion cards in the game represent the most common ions but do not provide a complete listing of ions.

Materials

Student Worksheet PDF

11948_Student1.pdf

11948_Teacher1.pdf

Teacher Tips

• Make a copy of the Rules for Game Play sheet for each player.
• Use the copy masters to copy one score sheet of either Game A or B and one List of Ion Cards for each player.
• Photocopy the ion cards on an acetate sheet. Cut out the sample cards. Use an overhead projector to demonstrate to students an acceptable match and an unacceptable match.
• Consider laminating the Go Fish for an Ion List of Ion Cards and Score Sheets; you may also wish to laminate the 64 cards for an extended lifetime.
• The Go Fish card game is an excellent review activity for students to play prior to a test. Or it can be a practice activity during the unit. The completed score sheets contain the cation, the anion and the compound formula and/or name so later the score sheet can be used as a study or review guide.

References

Special thanks to Laura Spencer, Edmonds–Woodway High School, Edmonds, WA, for providing the idea and instructions for this activity. Laura would like to thank her students for being the subjects on which to try and test this game.