Question

decide whether these proposed lewis structures are reasonable.
proposed lewis structure is the proposed lewis structure reasonable?
\\:n - n = n\\
yes.
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:
yes.
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:
yes.
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:

• 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 $[\text{N}-\text{N}\equiv\text{N}]^-$

N has 5 valence electrons. There are 3 N atoms, so total valence electrons from N is $3\times5 = 15$. The negative charge adds 1 more electron, so the total should be 16. In the given structure, counting the bonding and non - bonding electrons: single bond has 2 electrons, double bond has 4 electrons, triple bond has 6 electrons. There are 2 non - bonding pairs on the left N, 1 non - bonding pair on the middle N and no non - bonding pairs on the right N. Total electrons: $2 + 4+6+4 + 2=18$.

Step2: Check octet rule for $[\text{N}-\text{N}\equiv\text{N}]^-$

The left N has 6 electrons around it (2 non - bonding and 4 in bonds), so it doesn't satisfy the octet rule. The middle N has 8 electrons (2 non - bonding and 6 in bonds) and the right N has 8 electrons (in 6 bonds and 1 non - bonding pair).

Step3: Calculate valence - electrons for $\text{O}=\text{O}=\text{O}$

O has 6 valence electrons. For 3 O atoms, the total number of valence electrons should be $3\times6=18$. In the given structure, each double bond has 4 electrons. Total electrons: $4 + 4+4 = 12$.

Step4: Check octet rule for $\text{O}=\text{O}=\text{O}$

The middle O has 4 electrons around it (in 2 double bonds), so it doesn't satisfy the octet rule.

Step5: Calculate valence - electrons for $\text{Cl}-\text{N}-\text{Cl}$ with a $\text{Cl}$ above the $\text{N}$

N has 5 valence electrons and Cl has 7 valence electrons. There is 1 N and 3 Cl atoms. So total valence electrons are $5+3\times7 = 26$. In the given structure, each single bond has 2 electrons and each non - bonding pair has 2 electrons. Counting the electrons: 3 single bonds ($3\times2 = 6$) and non - bonding pairs: 9 non - bonding pairs ($9\times2=18$), total is $6 + 18=24$.

Step6: Check octet rule for $\text{Cl}-\text{N}-\text{Cl}$ with a $\text{Cl}$ above the $\text{N}$

The N atom has 6 electrons around it (in 3 single bonds), so it doesn't satisfy the octet rule.

Answer:

For $[\text{N}-\text{N}\equiv\text{N}]^-$: No, it has the wrong number of valence electrons. The correct number is 16. No, it has the right number of valence electrons but doesn't satisfy the octet rule. The symbols of the problem atoms are N.
For $\text{O}=\text{O}=\text{O}$: No, it has the wrong number of valence electrons. The correct number is 18. No, it has the right number of valence electrons but doesn't satisfy the octet rule. The symbols of the problem atoms are O.
For $\text{Cl}-\text{N}-\text{Cl}$ with a $\text{Cl}$ above the $\text{N}$: No, it has the wrong number of valence electrons. The correct number is 26. No, it has the right number of valence electrons but doesn't satisfy the octet rule. The symbols of the problem atoms are N.