Let’s analyze the number of unshared (lone) pairs on the designated atoms: ### First Structure - **Atom a (Oxygen in CH₃COOH, acetic acid):** - Oxygen in carboxylic acids typically has **2 lone pairs**. - **Atom b (Oxygen in CH₃COOH, the single-bonded oxygen):** - This oxygen is the *hydroxyl* oxygen (OH group), also typically with **2 lone pairs**. - **Atom c (Carbon in CH₃COOH, the central carbon):** - Carbon generally has **0 lone pairs** as it forms four bonds. ### Second Structure - **Atom a (Nitrogen in the ring):** - Nitrogen in a nitrile group (triple bond to carbon) has **1 lone pair**. - **Atom b (Oxygen in the five-membered ring):** - Oxygen typically has **2 lone pairs**. - **Atom c (Carbon in the ring):** - Carbon typically has **0 lone pairs**. ### Answers: **First Structure:** - The number of unshared pairs at atom a is: **2** - The number of unshared pairs at atom b is: **2** - The number of unshared pairs at atom c is: **0** **Second Structure:** - The number of unshared pairs at atom a is: **1** - The number of unshared pairs at atom b is: **2** - The number of unshared pairs at atom c is: **0** Let me know if you need the reasoning explained for each atom!