Which of the following is the correct Lewis structure for nitrogen gas [tex]$N_2$[/tex]?

A. [tex]$: \ddot{N}-\ddot{N}:$[/tex]

B. [tex][tex]$: N \equiv N:$[/tex][/tex]

C. [tex]$\ddot{ N }=\ddot{ N }$[/tex]



Answer :

To determine the correct Lewis structure for nitrogen gas ([tex]\(N_2\)[/tex]), we need to follow these steps:

1. Count the total number of valence electrons:
- Nitrogen ([tex]\(N\)[/tex]) is in Group 15 (also known as Group V) of the periodic table and has 5 valence electrons.
- Therefore, two nitrogen atoms will have a total of [tex]\(2 \times 5 = 10\)[/tex] valence electrons.

2. Determine the bonding pattern:
- Nitrogen atoms tend to form a triple bond to satisfy the octet rule because each nitrogen atom needs three more electrons to complete its octet.
- A triple bond consists of 6 electrons (3 pairs) being shared between the two nitrogen atoms.

3. Distribute the electrons:
- Start by placing three bonds (which count as 6 electrons) between the two nitrogen atoms:
[tex]\[ N \equiv N \][/tex]
- Each nitrogen atom will now have 2 electrons left (since we started with 10 electrons and used 6 for the triple bond).

4. Add lone pairs:
- Each nitrogen atom will have one lone pair (2 additional electrons).

Putting this all together, the Lewis structure for nitrogen gas ([tex]\(N_2\)[/tex]) is:

```
: N ≡ N :
```

Breaking it down, each nitrogen atom has:

- Three bonding pairs (6 electrons) in the triple bond.
- One lone pair (2 electrons).

This completes the octet for both nitrogen atoms (8 electrons each).

Thus, the correct Lewis structure for nitrogen gas ([tex]\(N_2\)[/tex]) is:
[tex]$ : N \equiv N : $[/tex]