Question

draw a lewis structure for carbonate, co₃²⁻. then carefully compare your drawing to the answer choices and select the correct choice.

Explanation:

To determine the correct Lewis structure for carbonate ($\ce{CO_3^{2-}}$), we analyze the valence electrons and bonding:

1. Valence Electrons: Carbon (C) has 4 valence electrons, each oxygen (O) has 6, and the 2- charge adds 2 more. Total: $4 + (3\times6) + 2 = 24$ electrons.
2. Bonding and Formal Charge: The carbonate ion has a trigonal planar structure with resonance. One C - O is a double bond, and two are single bonds (with each single - bonded O having 3 lone pairs, and the double - bonded O having 2 lone pairs) to satisfy the octet rule and formal charge (the overall charge is 2 - ). The structure should also show the 2 - charge with brackets.
3. Analyzing the Options:

• The first option (yellow) has a double bond but no bracket for the 2 - charge, so incorrect.
• The second option (purple) has a square - like bracket (incorrect shape for the ion's structure) and incorrect bonding (all single bonds would not satisfy the electron count and formal charge properly).
• The third option (orange) has no bracket for the 2 - charge and incorrect bonding (all single bonds with wrong lone pair counts).
• The fourth option (green) has the correct features: a double - bonded O (with 2 lone pairs), two single - bonded O atoms (each with 3 lone pairs), and the 2 - charge in brackets, matching the Lewis structure of $\ce{CO_3^{2-}}$.

Answer:

The correct option is the green - colored one (the fourth option from the top) with the Lewis structure showing a carbon atom double - bonded to one oxygen (with 2 lone pairs), single - bonded to two other oxygens (each with 3 lone pairs), and the 2 - charge in brackets around the structure.