decide whether these proposed lewis structures are reasonable. proposed lewis structure is the proposed lewis structure reasonable? yes. no, it has the wrong number of valence electrons. the correct number is: no, it has the right number of valence electrons but doesn’t satisfy the octet rule. the symbols of the problem atoms are:
The Correct Answer and Explanation is :
To evaluate whether proposed Lewis structures are reasonable, we typically consider two main criteria: the correct number of valence electrons and adherence to the octet rule. Let’s break down these criteria:
- Valence Electrons: Each atom has a specific number of valence electrons determined by its group number in the periodic table. To determine the total number of valence electrons for a molecule, we sum the valence electrons of each atom. For example, if a molecule consists of carbon (4 valence electrons), oxygen (6 valence electrons), and hydrogen (1 valence electron), we would calculate the total as follows:
- Carbon: 4
- Oxygen: 6
- Hydrogen (2): 2 × 1 = 2
- Total: 4 + 6 + 2 = 12 valence electrons
- Octet Rule: According to the octet rule, main-group elements tend to form bonds until they are surrounded by eight valence electrons, achieving a stable electron configuration similar to noble gases. This rule applies primarily to elements in periods 1 through 3. For example, carbon requires four bonds to fulfill the octet rule, while oxygen requires two.
Assessing the Proposed Lewis Structures
- Correct Number of Valence Electrons: If the proposed Lewis structure has the wrong number of total valence electrons compared to the calculated total, it is not reasonable. For example, if a structure for carbon dioxide (CO₂) has only 10 valence electrons instead of 16 (4 from carbon and 12 from two oxygens), it fails this criterion.
- Satisfying the Octet Rule: If a structure has the correct number of valence electrons but does not satisfy the octet rule for the relevant atoms, it is also deemed unreasonable. For instance, if a structure for ammonia (NH₃) shows nitrogen with only six valence electrons instead of eight, it would not satisfy the octet rule.
Conclusion
To decide if a proposed Lewis structure is reasonable, first verify the total number of valence electrons. If it is incorrect, note the correct number. If the count is correct, check if all atoms meet the octet rule. Structures failing either criterion are not reasonable.
If you have specific Lewis structures or atom symbols, please provide them for a more tailored analysis!