The $\pi$ electrons in benzene can be modelled as particles in a ring that follow Pauli's exclusion principle. Given that the radius of benzene is $1.4\,\mathrm{\AA}$, the longest wavelength of light that is absorbed during an electronic transition in benzene is ____ nm. (Upto one decimal place. Use $\mathrm{m_e}=9.1\times 10^{-31}\,\mathrm{kg}$, $\mathrm{h}=6.6\times 10^{-34}\,\mathrm{Js}$, $\mathrm{c}=3.0\times 10^{8}\,\mathrm{ms^{-1}}$)
(a)0
(b)$\hbar \mathrm{k}$
(c)$2 \hbar \mathrm{k}$
(d)$3 \hbar \mathrm{k}$
Answer
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