Which Lewis dot diagram represents an atom that needs 2 more electrons to complete its outermost shell?

• A. N with 5 dots around it
• B. O with 6 dots around it
• C. Ne with 8 dots around it
• D. F with 7 dots around it

Answer: (B)

Verified step by step guidance

1. Recall that the Lewis dot diagram represents the valence electrons of an atom, with each dot symbolizing one valence electron.
2. Identify the number of valence electrons each element has by looking at its group in the periodic table: Nitrogen (N) has 5, Oxygen (O) has 6, Fluorine (F) has 7, and Neon (Ne) has 8 valence electrons.
3. Understand that atoms tend to complete their outermost shell to have 8 electrons (the octet rule), except for some exceptions like hydrogen and helium.
4. Determine how many electrons each atom needs to reach 8: N needs 3 more, O needs 2 more, F needs 1 more, and Ne already has a full octet.
5. Conclude that the atom needing 2 more electrons to complete its outermost shell is the one with 6 valence electrons, which corresponds to Oxygen (O) with 6 dots around it.