Question

decide whether these proposed lewis structures are reasonable.
proposed lewis structure\tis the proposed lewis structure reasonable?
h = br\tyes.
no, it has the wrong number of valence electrons. the correct number is:
no, it has the right number of valence electrons but doesnt satisfy the octet rule. the symbols of the problem atoms are: *
o = c = o\tyes.
no, it has the wrong number of valence electrons. the correct number is:
no, it has the right number of valence electrons but doesnt satisfy the octet rule. the symbols of the problem atoms are: * o
n = n\tyes.
no, it has the wrong number of valence electrons. the correct number is: 10
no, it has the right number of valence electrons but doesnt satisfy the octet rule. the symbols of the problem atoms are: *

• if two or more atoms of the same element dont satisfy the octet rule, just enter the chemical symbol as many times as necessary. for example, if two oxygen atoms dont satisfy the octet rule, enter \o,o\.

Explanation:

Step1: Calculate valence electrons for H - Br

Hydrogen has 1 valence electron and bromine has 7 valence electrons, so in total there should be $1 + 7=8$ valence electrons. The proposed structure has a double - bond which implies an incorrect count.

Step2: Analyze O = C = O

Oxygen has 6 valence electrons and carbon has 4 valence electrons. For $CO_2$, the total number of valence electrons is $2\times6 + 4=16$. The given structure has the correct number of valence electrons and satisfies the octet rule for all atoms (carbon has 8 electrons around it and each oxygen has 8 electrons around it).

Step3: Calculate valence electrons for N = N

Nitrogen has 5 valence electrons. For $N_2$, the total number of valence electrons is $2\times5 = 10$. The proposed structure has an incorrect number of valence electrons.

Answer:

1. No, it has the wrong number of valence electrons. The correct number is: 8
2. Yes.
3. No, it has the wrong number of valence electrons. The correct number is: 10