In accordance with the octet rule, which of the following atoms is most likely to form an ion with a -1 charge?

• A. Ne
• B. Na
• C. Mg
• D. Cl

Answer: (D)

Verified step by step guidance

1. Understand the octet rule: atoms tend to gain, lose, or share electrons to achieve a full outer shell of 8 electrons, which is a stable electronic configuration similar to noble gases.
2. Identify the electron configurations of the given atoms: Ne (neon) is a noble gas with a full octet, Na (sodium) has 1 electron in its outer shell, Mg (magnesium) has 2 electrons in its outer shell, and Cl (chlorine) has 7 electrons in its outer shell.
3. Determine the tendency to gain or lose electrons based on their valence electrons: atoms with nearly full outer shells tend to gain electrons to complete the octet, while those with few valence electrons tend to lose them.
4. Since Cl has 7 valence electrons, it is most likely to gain 1 electron to complete its octet, forming an ion with a -1 charge (Cl⁻).
5. Ne is already stable with a full octet and typically does not form ions; Na and Mg tend to lose electrons to form positive ions (Na⁺ and Mg²⁺ respectively), so they are unlikely to form a -1 charged ion.