Question

question 10 of 40
consider these structures,

methylene

ethyl radical

for which structure or structures does the
electron - bearing carbon atom have a formal charge
of 0?
○ methylene only
○ neither
○ both
○ ethyl radical only

for which structure or structures is the net charge 0?
○ ethyl radical only
○ neither
○ both
○ methylene only

Explanation:

Step1: Define formal charge formula

Formal charge = $V - N - \frac{B}{2}$, where $V$ = valence electrons of C (4), $N$ = nonbonding electrons, $B$ = bonding electrons.

Step2: Calculate formal charge for methylene C

Methylene: $N=2$, $B=4$ (2 single bonds)
Formal charge = $4 - 2 - \frac{4}{2} = 4-2-2=0$

Step3: Calculate formal charge for ethyl radical C

Ethyl radical: $N=1$, $B=6$ (3 single bonds)
Formal charge = $4 - 1 - \frac{6}{2} = 4-1-3=0$

Step4: Determine net charge for both

Both structures have no overall ionic charge; all atoms have formal charges summing to 0.

Answer:

First question (formal charge 0 on electron-bearing C):

both

Second question (net charge 0):

both