Question

decide whether these proposed lewis structures are reasonable.
proposed lewis structure is the proposed lewis structure reasonable?
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*
h−c≡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*
h−c−c−h
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 write 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 $N - N$

N has 5 valence electrons each. For $N - N$, the total should be $5\times2 = 10$. The given structure doesn't account for all valence - electrons.

Step2: Analyze $H - C\equiv N$

H has 1 valence electron, C has 4, and N has 5. Total valence electrons: $1 + 4+5=10$. The structure has a triple - bond between C and N and single - bond between C and H, satisfying the octet rule for C and N and duet rule for H.

Step3: Analyze $H - C - C - H$

H has 1 valence electron each (2 H's give 2 electrons), C has 4 valence electrons each (2 C's give 8 electrons), total is 10 valence electrons. But the C atoms only have 6 electrons around them, violating the octet rule.

Answer:

1.

• For $N - N$:
• No, it has the wrong number of valence electrons. The correct number is 10.
• For $H - C\equiv N$:
• Yes.
• For $H - C - C - H$:
• No, it has the right number of valence electrons but doesn't satisfy the octet rule. The symbols of the problem atoms are C, C.