Question

An aromatic compounds among other things should have a $(4n+2)$ $\pi -$ electron cloud, where $n$ can't be:

• A. $\frac{1}{2}$
• B. $3$
• C. $2$
• D. $1$

Answer 1

The correct option is A $\frac{1}{2}$

For any system to be aromatic, it must be planar, cyclic, contain conjugated $\pi$electrons and it must follow Huckel's rule. According to Huckel's rule, if a cyclic, planar, conjugated molecule has $(4n+2)\pi$ electrons, it is aromatic.
where $n$ can only be positive integer $i.e.0,1,2,\mathrm{3...}$ , it cannot be fractional or negative.