AP Chemistryeasymcq1 pt
How many valence electrons must be accounted for in the Lewis structure of hydrogen cyanide, HCN?
A.8
B.10
C.16
D.12
Explanation
Core Concept
Hydrogen brings 1, carbon 4, and nitrogen 5, so 1 + 4 + 5 = 10 electrons fill the C-H bond, the C≡N triple bond, and nitrogen's lone pair. Counting group numbers before drawing prevents octet errors later. Neutral molecules use exactly this total with no adjustment for charge.
Correct Answer
B10
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