Determine the Lewis structure of O2? oxygen gas. Step 1: Complete the Lewis dot symbols for the oxygen atoms below 00 Step 2: Determine the number of valence electrons available in the O2? molecule. total valence electrons = Use two of these electrons to make a bond between the 2 oxygen atoms. 0:0 Step 3: Determine the number of unused valence electrons. Step 4: Place the remaining electrons as pairs of electrons around the O2? structure. 0:0 Does each of the 0 atoms have an octet of electrons?
The Correct Answer and Explanation is :
Lewis Structure of O₂ (Oxygen Gas)
Step 1: Lewis Dot Symbols for Oxygen Atoms
Each oxygen atom has 6 valence electrons (since oxygen is in Group 16 of the periodic table). The Lewis dot symbols for two oxygen atoms are:
[
\cdot \cdot O \cdot \cdot
]
[
\cdot \cdot O \cdot \cdot
]
Step 2: Total Valence Electrons in O₂
Each oxygen atom has 6 valence electrons, so for the O₂ molecule:
[
6 + 6 = 12 \text{ total valence electrons}
]
Two of these electrons will be used to form a bond between the oxygen atoms.
Step 3: Determine the Number of Unused Valence Electrons
After forming a single bond, we subtract 2 electrons, leaving:
[
12 – 2 = 10 \text{ electrons remaining}
]
Step 4: Distribute the Remaining Electrons
The remaining 10 electrons are placed around both oxygen atoms. However, when placing electrons, we must ensure that each atom satisfies the octet rule (having 8 electrons in its valence shell). Placing the electrons as lone pairs leads to the realization that a single bond is insufficient to complete both octets.
To satisfy the octet rule, a second bond must form, creating a double bond between the oxygen atoms:
[
\cdot \cdot O = O \cdot \cdot
]
Each oxygen atom now has:
- 4 bonding electrons (from the double bond)
- 4 nonbonding electrons (two lone pairs)
This results in each oxygen atom having 8 valence electrons, satisfying the octet rule.
Final Lewis Structure of O₂
[
\cdot \cdot O = O \cdot \cdot
]
Explanation (300 Words)
Oxygen gas (O₂) is composed of two oxygen atoms, each with 6 valence electrons. To determine its Lewis structure, we begin by considering the total valence electrons, which is 12 (6 from each oxygen atom). Initially, a single bond (O–O) would leave each oxygen atom with only 7 electrons, violating the octet rule.
To resolve this, a double bond (O=O) is formed, using 4 electrons (2 pairs) to create a stronger bond between the atoms. This leaves 4 electrons per oxygen atom as lone pairs, satisfying the octet rule.
The O₂ molecule exhibits paramagnetism, meaning it has unpaired electrons in its molecular orbital theory, which is not evident in the simple Lewis structure. However, in Lewis structures, the double bond representation is the most accepted form.
Thus, the correct Lewis structure of O₂ is O=O, where each oxygen has 8 valence electrons (4 from the bond and 4 from lone pairs), satisfying the octet rule.