Which of the following Lewis dot structures correctly represents the neutral compound CaCl_2?

• A. Ca atom with 8 dots, each Cl atom with 8 dots
• B. Ca atom with 2 dots, each Cl atom with 7 dots, all atoms neutral
• C. Ca^{2+} surrounded by two Cl^{-} ions, each Cl with 8 valence electrons (full octet), and no electrons shown on Ca
• D. Ca^{2+} bonded to two Cl atoms, each Cl with 6 dots

Answer: (C)

Verified step by step guidance

1. Step 1: Identify the type of compound and bonding involved. CaCl_2 is an ionic compound formed between a metal (Ca) and nonmetals (Cl). Calcium tends to lose electrons to form a cation, and chlorine tends to gain electrons to form anions.
2. Step 2: Determine the electron configuration changes. Calcium (Ca) has 2 valence electrons and will lose both to form Ca^{2+}. Each chlorine atom (Cl) has 7 valence electrons and will gain 1 electron to complete its octet, becoming Cl^{-}.
3. Step 3: Draw the Lewis structure showing the ions. Represent Ca as Ca^{2+} with no dots around it because it has lost its valence electrons. Each Cl atom should be shown with 8 dots (representing a full octet) and a negative charge to indicate the gained electron.
4. Step 4: Confirm the neutrality of the compound. The overall charge must be zero, so one Ca^{2+} ion balances two Cl^{-} ions, resulting in a neutral compound CaCl_2.
5. Step 5: Understand why other options are incorrect. Neutral atoms with dots around Ca or Cl do not represent the ionic nature of CaCl_2. The correct Lewis structure must show Ca^{2+} and Cl^{-} ions with appropriate charges and full octets on Cl.