June 2023 NY Regents Chemistry Exam
31 Which Lewis electron-dot diagram represents an atom of nitrogen in the ground state?
Solution:The dots represent the number of valence electrons (electrons in the outer shell). Looking at the Periodic Table, we can see the electron configuration of nitrogen is 2-5. The last number is 5 which means nitrogen has 5 valence electrons. We are looking for a structure with 5 dots. Alternately, Group 1 has 1 valence electron, 2 is 2 valence electrons, group 13 is 3, 14 is 4, 15 is 5, 16 is 6, 17 is 7 and 18 is 8.
Answer:2
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