Question

a lewis structure with placeholder elements is shown. if the formal charge of the central atom is +1, choose the possible identity or identities of the central atom.

Explanation:

Step1: Recall formal charge formula

Formal charge \(FC = V - N - \frac{B}{2}\), where \(V\) is the number of valence electrons, \(N\) is the number of non - bonding electrons, and \(B\) is the number of bonding electrons.

Step2: Analyze the structure

The central atom has two double bonds (\(B = 8\), since each double bond has 4 electrons and there are two double bonds). Let's assume \(N = 0\) (from the structure's appearance, no lone pairs shown on central atom for this analysis of bonding situation).

Step3: Calculate \(V\) for \(FC= + 1\)

Using \(FC = V - N-\frac{B}{2}\), substitute \(FC = + 1\), \(N = 0\), \(B = 8\). Then \(1=V - 0-\frac{8}{2}\). Solving for \(V\): \(V=1 + 4=5\).

Step4: Check valence electrons of options

• Option A (\(F\)): Valence electrons \(V = 7\).
• Option B (\(O,S,Se\)): Valence electrons \(V = 6\).
• Option C (\(B,Al\)): Valence electrons \(V = 3\).
• Option D (\(N,P,As\)): Valence electrons \(V = 5\).
• Option E (\(Cl,Br,I\)): Valence electrons \(V = 7\).

Answer:

D. N, P, or As