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: none
Lesson: 40 minutes (including whole class debrief)
- One student handout per student
- No specific safety precautions need to be observed for this activity.
- Teachers should be familiar with the rules for naming and formula writing for covalent compounds.
- 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 helpful in guiding students through the questions.
- 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.
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 covalent compounds.