Summary

In this game, students will use their knowledge of the different types of elements and the compounds they can form to guess the computer opponent’s secret compound before the computer can identify their compound. Students will take turns with the computer asking and answering yes or no questions about their secret compounds, selected from a pool of 20 compounds, to try to narrow down the pool to identify the computer’s compound first. This activity encourages students to reflect on different ways matter can be classified.

Grade Level

Middle School, High School

NGSS Alignment

This game will help prepare your students to meet the performance expectations in the following standards:

• MS-PS1-1: Develop models to describe atomic composition of simple molecules and extended structures.
• Scientific and Engineering Practices:
  • Developing and Using Models

Objectives

By the end of this game, students should be able to:

• Identify different ways of classifying elements and compounds.
• Distinguish between ionic and covalent compounds based on the elements they contain.

Chemistry Topics

This game supports students’ understanding of:

• Elements
• Periodic table
• Ionic and covalent bonding

Time

Teacher Preparation: minimal
Lesson: 30 minutes

Materials

• Student handout
• Device connected to the Internet
• Access to game: https://teachchemistry.org/classroom-resources/guess-what-compounds-game

Safety

• No specific safety precautions need to be observed for this activity.

Teacher Notes

• The game can be found at the following link (note that students can access the simulation without an AACT login):
  • https://teachchemistry.org/classroom-resources/guess-what-compounds-game
• In this game, students will race to beat the computer to determining the identity of its secret compound before it can identify theirs. They will start with a pool of 20 compounds and will ask and answer a series of yes or no questions to eliminate compounds until they narrow it down to the secret compound, or the computer identifies theirs. Questions students can choose from include information about the type of compound (ionic or covalent), the presence of specific elements, and the presence of a type of element (halogen, transition metal, etc.), among others.
• This game can be used with middle or high school students once they have learned about the sections of periodic table and various ways of classifying elements, as well as the basics of ionic and covalent compounds. Primarily, they need to be able to identify that ionic compounds consist of a metal + nonmetal or polyatomic ion, and covalent compounds consist of nonmetals only or a nonmetal + metalloid. They do not need to know anything more detailed about ionic or covalent bonding.
  • Note that, even though polyatomic ions do contain covalent bonds, the overall compound is ionic, so any compound that contains a polyatomic ion is classified as ionic.
• The questions “Is your compound classified as ionic?” and “Is your compound classified as covalent?” are both included as options in the game, but because all of the compounds in the game are one or the other, it is redundant to ask both. Students may notice this as use this as a strategy, or it could be worth having a conversation about whether any of the questions in the game are redundant. This discussion could continue with the final challenge question in the student handout, where students consider other ways matter (not just compounds, but any matter) can be classified. Some other classifications include mixtures (alloys, solutions, homogeneous or heterogeneous), polar covalent compounds (between ionic and covalent/non-polar on the polarity spectrum), pure elements (including diatomic/polyatomic elements), etc.
• There are 32 possible secret compounds, and 20 will be randomly selected to be on the board each game, so the game board and the available compounds will be different for every game. At the start of the game, students will be randomly assigned one of the 20 compounds on the board as their secret compound.
• The computer and student will have the same 20 compounds on their boards in a given game.
• Based on the compounds that are on the board, students can strategically choose what questions will be most useful in a given game. For example, if there are no compounds on the board that contain a metalloid, then asking the question “Does your compound contain a metalloid?” is a waste of a turn. The computer does not take the board layout into consideration and asks questions at random.
• There is a counter that shows how many possible compounds remain for the computer’s guess of the student’s compound. At any point in the game, students can use a turn to randomly guess what the computer’s compound is, particularly if they see the computer getting close to identifying their compound.
• This game could be used as an intro activity for a Chemical Names and Formulas Unit Plan.
• The student handout is divided into three parts:
  • Part 1 should be completed prior to beginning the game as it primes students to think about various ways elements and compounds can be classified, which will be used in the game to help them identify a secret compound.
  • Part 2 should be completed after playing the game as it challenges the students to come up with examples of compounds that meet a set of criteria similar to those used in the game, or to come up with a set of criteria that describes a set of compounds provided.
  • The final “Challenge” portion of the student handout has students think of other ways matter can be classified that were not reflected in the questions in the game and to provide examples of matter that fit in those categories.
• An Answer Key document is available for teacher reference.