In this lesson, students engage their literacy skills to interpret tables and answer a series of guiding questions to discover the rules of naming and formula writing for simple covalent compounds.
By the end of this lesson, students should be able to
- Write a chemical formula for a covalent compound
- Name a covalent compound using the appropriate rules of nomenclature
- Covalent nomenclature and formula writing
Teacher Preparation: minimal
Lesson: 40 minutes (including whole class debrief)
- One student handout per student
- No specific safety precautions need to be observed for this activity.
- I have found it helpful to introduce the activity, have students work in pairs and then debrief as a class and/or have students complete an exit slip at the end of the class time.
- Walking around to monitor student progress and check for understanding is very important in ensuring students that are fully comprehending that material being presented.
- For higher levels you could include more names and formulas for lower levels you could break the tables into smaller chucks so students can focus on the inquiry.
For the Student
I am learning how to name a molecular compound and write a chemical formula.
Name of compound
In Table 1 above, several covalently bonded molecules are listed. The names and chemical formulas have been provided. Use the information in the table to answer the following questions:
- What do you notice about the types of elements in the chemical formulas?
- What do you notice about the ending of the names for the above compounds?
- Other than a prefix, what do you notice about the names of first element in the chemical formulas compared to the periodic table?
- Find the compound names that contain “di” as a prefix. What do you notice about their chemical formulas?
- Find the compound names that contain “tri” as a prefix. What do you notice about their chemical formulas?
- Predict the number of atoms based on the prefix by filing in Table 2.
|Prefix||Number of atoms|
- The subscript is the little number that comes after a chemical symbol. Based on the information above and the picture below, what does the subscript indicate?
- Using the example below, what is the subscript after the first element in each of the following compounds: CO2, CCl4 and SiO2?
- Find one other compound in Table 1 that follows a similar pattern as the compounds listed in question 8.
|Name of compound||Chemical formula|
- Using Table 3, does the first subscript listed in a chemical formula correspond with prefix for the first or second element?
- Compare and contrast the name and chemical formula for compounds in Table 3: when is the prefix “mono” included in the name?
- Write the names of the following covalent compounds:
- SO3 __________________
- N2S __________________
- P2Br4 _________________
- CO __________________
- SF6 __________________
- NO2 __________________
- Write the formulas of the following covalent compounds:
- nitrogen trichloride _______________________
- boron monocarbide _______________________
- dinitrogen trioxide ________________________
- phosphorus pentafluoride __________________
- diboron tetrahydride ______________________
- oxygen difluoride _________________________
- Summarize the rules for naming covalent compounds.
- Summarize the rules for writing formulas for covalent compounds.