Write the correct Lewis dot structure for O2. Which statement correctly describes the structure of the whole molecule?
A. There is a single bond, a double bond, and six lone pairs.
B. There is a single bond and four lone pairs.
C. There is a single bond and six lone pairs.
D. There is a double bond and six lone pairs.
The Correct Answer and Explanation is:
The correct answer is D. There is a double bond and six lone pairs.
Explanation:
To draw the Lewis dot structure for the O₂ molecule, we first need to understand the bonding and electron arrangement.
- Count the total number of valence electrons:
Oxygen (O) is in Group 16 of the periodic table, meaning each oxygen atom has 6 valence electrons. Since there are two oxygen atoms in O₂, the total number of valence electrons is:
[
6 \, (\text{valence electrons for O}) \times 2 = 12 \, \text{valence electrons}.
] - Form the bond:
The two oxygen atoms will share electrons to form a covalent bond. A single bond consists of two shared electrons. However, because each oxygen atom needs to fulfill the octet rule (eight electrons around each atom), a single bond is not sufficient. We need to form a double bond (a bond involving four shared electrons). This gives each oxygen atom a total of 8 electrons in its valence shell. - Place the lone pairs:
After forming the double bond, we have used 4 electrons for the bond. There are 12 total electrons to place, so 8 electrons remain. These 8 remaining electrons will be placed as lone pairs on the oxygen atoms. Each oxygen atom will have 2 lone pairs of electrons (4 electrons), leaving 4 electrons remaining. These 4 electrons will be placed as a lone pair on each oxygen atom, completing the octet for both atoms. - Final structure:
- The two oxygen atoms are connected by a double bond.
- Each oxygen atom has two lone pairs of electrons.
- Therefore, the structure is O=O, with six lone pairs of electrons in total (four on the two oxygen atoms and two from the double bond electrons).
Thus, the correct description of the Lewis structure is D. There is a double bond and six lone pairs.
Further clarification:
In the O₂ molecule, the bonding is a double bond, which consists of one sigma bond and one pi bond. Each oxygen atom also has two lone pairs. This gives a stable configuration where both atoms achieve an octet of electrons.