a. Draw the resonance forms for SO₂ (bonded O–S–O).

Verified step by step guidance

1. Identify the central atom in the molecule, which is sulfur (S) in this case, and note that it is bonded to two oxygen (O) atoms.
2. Determine the total number of valence electrons available. Sulfur has 6 valence electrons, and each oxygen has 6 valence electrons, giving a total of 18 valence electrons for SO2.
3. Draw the initial Lewis structure with sulfur in the center and single bonds to each oxygen atom. Distribute the remaining electrons to satisfy the octet rule for the oxygen atoms first.
4. Consider the possibility of resonance by moving a lone pair of electrons from one of the oxygen atoms to form a double bond with sulfur, creating a resonance structure. Repeat this process for the other oxygen atom.
5. Depict the resonance structures by showing the movement of electrons with arrows and draw the resulting structures, ensuring that the formal charges are minimized and the octet rule is satisfied for each atom.

Key Concepts

Resonance Structures

Resonance structures are different Lewis structures for a molecule that depict the same arrangement of atoms but differ in the distribution of electrons. They are used to represent molecules where electron delocalization occurs, providing a more accurate depiction of the molecule's electronic structure. In the case of SO2, resonance structures help illustrate the delocalization of electrons between the sulfur and oxygen atoms.

Lewis Structures

Lewis structures are diagrams that represent the bonding between atoms of a molecule and the lone pairs of electrons that may exist. They are essential for visualizing the arrangement of electrons in molecules, which is crucial for understanding molecular geometry, reactivity, and resonance. For SO2, drawing the Lewis structure involves accounting for the valence electrons of sulfur and oxygen to form bonds and lone pairs.

Formal Charge

Formal charge is a concept used to determine the most stable resonance structure by calculating the charge distribution within a molecule. It is calculated by subtracting the number of electrons assigned to an atom in a Lewis structure from the number of valence electrons in the free atom. For SO2, evaluating formal charges helps identify the most plausible resonance structures by minimizing charge separation and ensuring the most stable configuration.